diff --git a/src-tauri/src/services/omo.rs b/src-tauri/src/services/omo.rs
index 525ae03d4..0f2038e48 100644
--- a/src-tauri/src/services/omo.rs
+++ b/src-tauri/src/services/omo.rs
@@ -286,6 +286,18 @@ impl OmoService {
 
         let obj = Self::read_jsonc_object(&actual_path)?;
 
+        Ok(Self::build_local_file_data_from_obj(
+            &obj,
+            actual_path.to_string_lossy().to_string(),
+            last_modified,
+        ))
+    }
+
+    fn build_local_file_data_from_obj(
+        obj: &Map<String, Value>,
+        file_path: String,
+        last_modified: Option<String>,
+    ) -> OmoLocalFileData {
         let agents = obj.get("agents").cloned();
         let categories = obj.get("categories").cloned();
 
@@ -298,15 +310,16 @@ impl OmoService {
 
         let mut global = OmoGlobalConfig::default();
         Self::merge_global_from_obj(&obj, &mut global);
+        global.other_fields = other_fields.clone();
 
-        Ok(OmoLocalFileData {
+        OmoLocalFileData {
             agents,
             categories,
             other_fields,
             global,
-            file_path: actual_path.to_string_lossy().to_string(),
+            file_path,
             last_modified,
-        })
+        }
     }
 
     fn strip_jsonc_comments(input: &str) -> String {
@@ -434,4 +447,58 @@ mod tests {
         assert!(!obj.contains_key("disabled_agents"));
         assert!(obj.contains_key("agents"));
     }
+
+    #[test]
+    fn test_build_local_file_data_keeps_unknown_top_level_fields_in_global() {
+        let obj = serde_json::json!({
+            "$schema": "https://example.com/schema.json",
+            "disabled_agents": ["oracle"],
+            "agents": {
+                "sisyphus": { "model": "claude-opus-4-6" }
+            },
+            "categories": {
+                "code": { "model": "gpt-5.3" }
+            },
+            "custom_top_level": {
+                "enabled": true
+            }
+        });
+        let obj_map = obj.as_object().unwrap().clone();
+
+        let data = OmoService::build_local_file_data_from_obj(
+            &obj_map,
+            "/tmp/oh-my-opencode.jsonc".to_string(),
+            None,
+        );
+
+        assert_eq!(data.global.schema_url.as_deref(), Some("https://example.com/schema.json"));
+        assert_eq!(data.global.disabled_agents, vec!["oracle".to_string()]);
+
+        assert_eq!(
+            data.other_fields,
+            Some(serde_json::json!({
+                "custom_top_level": { "enabled": true }
+            }))
+        );
+        assert_eq!(data.global.other_fields, data.other_fields);
+    }
+
+    #[test]
+    fn test_merge_config_ignores_non_object_other_fields() {
+        let global = OmoGlobalConfig {
+            other_fields: Some(serde_json::json!(["global_non_object"])),
+            ..Default::default()
+        };
+        let agents = None;
+        let categories = None;
+        let other_fields = Some(serde_json::json!("profile_non_object"));
+        let profile_data = (agents, categories, other_fields, true);
+
+        let merged = OmoService::merge_config(&global, Some(&profile_data));
+        let obj = merged.as_object().unwrap();
+
+        assert!(!obj.contains_key("0"));
+        assert!(!obj.contains_key("global_non_object"));
+        assert!(!obj.contains_key("profile_non_object"));
+    }
 }
diff --git a/src/components/providers/forms/OmoFormFields.tsx b/src/components/providers/forms/OmoFormFields.tsx
index 9ec647472..b4b859ba8 100644
--- a/src/components/providers/forms/OmoFormFields.tsx
+++ b/src/components/providers/forms/OmoFormFields.tsx
@@ -77,7 +77,11 @@ interface OmoFormFieldsProps {
   onOtherFieldsStrChange: (value: string) => void;
 }
 
-type CustomModelItem = { key: string; model: string };
+export type CustomModelItem = {
+  key: string;
+  model: string;
+  sourceKey?: string;
+};
 type BuiltinModelDef = Pick<
   OmoAgentDef | OmoCategoryDef,
   "key" | "display" | "descKey" | "recommended" | "tooltipKey"
@@ -236,45 +240,58 @@ function collectCustomModels(
       customs.push({
         key: k,
         model: ((v as Record<string, unknown>).model as string) || "",
+        sourceKey: k,
       });
     }
   }
   return customs;
 }
 
-function mergeCustomModelsIntoStore(
+export function mergeCustomModelsIntoStore(
   store: Record<string, Record<string, unknown>>,
   builtinKeys: Set<string>,
   customs: CustomModelItem[],
   modelVariantsMap: Record<string, string[]>,
 ): Record<string, Record<string, unknown>> {
-  const updated = { ...store };
-  for (const key of Object.keys(updated)) {
-    if (!builtinKeys.has(key)) delete updated[key];
+  const updated: Record<string, Record<string, unknown>> = {};
+
+  for (const [key, value] of Object.entries(store)) {
+    if (builtinKeys.has(key)) {
+      updated[key] = { ...value };
+    }
   }
+
   for (const custom of customs) {
-    if (custom.key.trim()) {
-      const nextEntry = { ...(updated[custom.key] || {}) };
-      if (custom.model.trim()) {
-        nextEntry.model = custom.model;
-        const currentVariant =
-          typeof nextEntry.variant === "string" ? nextEntry.variant : "";
-        if (currentVariant) {
-          const validVariants = modelVariantsMap[custom.model] || [];
-          if (!validVariants.includes(currentVariant)) {
-            delete nextEntry.variant;
-          }
-        }
-        updated[custom.key] = nextEntry;
-      } else {
-        delete nextEntry.model;
-        delete nextEntry.variant;
-        if (Object.keys(nextEntry).length > 0) {
-          updated[custom.key] = nextEntry;
-        } else {
-          delete updated[custom.key];
+    const targetKey = custom.key.trim();
+    if (!targetKey) continue;
+
+    const sourceKey = (custom.sourceKey || targetKey).trim();
+    const sourceEntry = store[sourceKey] ?? store[targetKey];
+    const nextEntry = {
+      ...(updated[targetKey] || {}),
+      ...(sourceEntry || {}),
+    };
+
+    if (custom.model.trim()) {
+      nextEntry.model = custom.model;
+      const currentVariant =
+        typeof nextEntry.variant === "string" ? nextEntry.variant : "";
+      if (currentVariant) {
+        const validVariants = modelVariantsMap[custom.model] || [];
+        if (!validVariants.includes(currentVariant)) {
+          delete nextEntry.variant;
         }
       }
+      updated[targetKey] = nextEntry;
+      continue;
+    }
+
+    delete nextEntry.model;
+    delete nextEntry.variant;
+    if (Object.keys(nextEntry).length > 0) {
+      updated[targetKey] = nextEntry;
+    } else {
+      delete updated[targetKey];
     }
   }
   return updated;
@@ -1032,11 +1049,17 @@ export function OmoFormFields({
 
   const addCustomModel = (scope: AdvancedScope) => {
     if (scope === "agent") {
-      setCustomAgents((prev) => [...prev, { key: "", model: "" }]);
+      setCustomAgents((prev) => [
+        ...prev,
+        { key: "", model: "", sourceKey: "" },
+      ]);
       setSubAgentsOpen(true);
       return;
     }
-    setCustomCategories((prev) => [...prev, { key: "", model: "" }]);
+    setCustomCategories((prev) => [
+      ...prev,
+      { key: "", model: "", sourceKey: "" },
+    ]);
     setCategoriesOpen(true);
   };
 
diff --git a/src/components/providers/forms/ProviderForm.tsx b/src/components/providers/forms/ProviderForm.tsx
index d1c909720..381a7d68c 100644
--- a/src/components/providers/forms/ProviderForm.tsx
+++ b/src/components/providers/forms/ProviderForm.tsx
@@ -54,7 +54,7 @@ import { type OmoGlobalConfigFieldsRef } from "./OmoGlobalConfigFields";
 import { OmoCommonConfigEditor } from "./OmoCommonConfigEditor";
 import * as configApi from "@/lib/api/config";
 import type { OmoGlobalConfig } from "@/types/omo";
-import { mergeOmoConfigPreview } from "@/types/omo";
+import { mergeOmoConfigPreview, parseOmoOtherFieldsObject } from "@/types/omo";
 import {
   ProviderAdvancedConfig,
   type PricingModelSourceOption,
@@ -219,8 +219,10 @@ function buildOmoProfilePreview(
   }
   if (otherFieldsStr.trim()) {
     try {
-      const other = JSON.parse(otherFieldsStr);
-      Object.assign(profileOnly, other);
+      const other = parseOmoOtherFieldsObject(otherFieldsStr);
+      if (other) {
+        Object.assign(profileOnly, other);
+      }
     } catch {}
   }
   return profileOnly;
@@ -1203,7 +1205,19 @@ export function ProviderForm({
       }
       if (omoOtherFieldsStr.trim()) {
         try {
-          omoConfig.otherFields = JSON.parse(omoOtherFieldsStr);
+          const otherFields = parseOmoOtherFieldsObject(omoOtherFieldsStr);
+          if (!otherFields) {
+            toast.error(
+              t("omo.jsonMustBeObject", {
+                field: t("omo.otherFields", {
+                  defaultValue: "Other Config",
+                }),
+                defaultValue: "{{field}} must be a JSON object",
+              }),
+            );
+            return;
+          }
+          omoConfig.otherFields = otherFields;
         } catch {
           toast.error(
             t("omo.invalidJson", {
diff --git a/src/types/omo.ts b/src/types/omo.ts
index e450c20a1..8b6059223 100644
--- a/src/types/omo.ts
+++ b/src/types/omo.ts
@@ -316,6 +316,17 @@ export const OMO_CLAUDE_CODE_PLACEHOLDER = `{
   "plugins": true
 }`;
 
+export function parseOmoOtherFieldsObject(
+  raw: string,
+): Record<string, unknown> | undefined {
+  if (!raw.trim()) return undefined;
+  const parsed: unknown = JSON.parse(raw);
+  if (typeof parsed !== "object" || parsed === null || Array.isArray(parsed)) {
+    return undefined;
+  }
+  return parsed as Record<string, unknown>;
+}
+
 export function mergeOmoConfigPreview(
   global: OmoGlobalConfig,
   agents: Record<string, Record<string, unknown>>,
@@ -351,7 +362,8 @@ export function mergeOmoConfigPreview(
   if (Object.keys(agents).length > 0) result["agents"] = agents;
   if (Object.keys(categories).length > 0) result["categories"] = categories;
   try {
-    const other = JSON.parse(otherFieldsStr || "{}");
+    const other = parseOmoOtherFieldsObject(otherFieldsStr);
+    if (!other) return result;
     for (const [k, v] of Object.entries(other)) {
       result[k] = v;
     }
diff --git a/tests/components/OmoFormFields.mergeCustomModelsIntoStore.test.ts b/tests/components/OmoFormFields.mergeCustomModelsIntoStore.test.ts
new file mode 100644
index 000000000..b77b79e60
--- /dev/null
+++ b/tests/components/OmoFormFields.mergeCustomModelsIntoStore.test.ts
@@ -0,0 +1,111 @@
+import { describe, expect, it } from "vitest";
+import {
+  mergeCustomModelsIntoStore,
+  type CustomModelItem,
+} from "@/components/providers/forms/OmoFormFields";
+
+describe("mergeCustomModelsIntoStore", () => {
+  it("保留自定义项高级字段，并在模型变更时仅按需清理非法 variant", () => {
+    const store = {
+      sisyphus: { model: "builtin-model" },
+      "custom-agent": {
+        model: "model-a",
+        variant: "fast",
+        temperature: 0.2,
+        permission: { edit: "allow" },
+      },
+    };
+    const customs: CustomModelItem[] = [
+      { key: "custom-agent", model: "model-b", sourceKey: "custom-agent" },
+    ];
+
+    const merged = mergeCustomModelsIntoStore(
+      store,
+      new Set(["sisyphus"]),
+      customs,
+      { "model-b": ["precise"] },
+    );
+
+    expect(merged.sisyphus).toEqual({ model: "builtin-model" });
+    expect(merged["custom-agent"]).toEqual({
+      model: "model-b",
+      temperature: 0.2,
+      permission: { edit: "allow" },
+    });
+  });
+
+  it("重命名自定义 key 时迁移原有 variant 和高级字段", () => {
+    const store = {
+      sisyphus: { model: "builtin-model" },
+      "custom-agent-old": {
+        model: "model-a",
+        variant: "fast",
+        maxTokens: 8192,
+      },
+    };
+    const customs: CustomModelItem[] = [
+      {
+        key: "custom-agent-new",
+        sourceKey: "custom-agent-old",
+        model: "model-a",
+      },
+    ];
+
+    const merged = mergeCustomModelsIntoStore(
+      store,
+      new Set(["sisyphus"]),
+      customs,
+      { "model-a": ["fast", "balanced"] },
+    );
+
+    expect(merged["custom-agent-old"]).toBeUndefined();
+    expect(merged["custom-agent-new"]).toEqual({
+      model: "model-a",
+      variant: "fast",
+      maxTokens: 8192,
+    });
+  });
+
+  it("custom 列表为空时移除旧自定义项但保留内置项", () => {
+    const store = {
+      sisyphus: { model: "builtin-model" },
+      hephaestus: { model: "builtin-model-2" },
+      "custom-agent": { model: "model-a", temperature: 0.3 },
+    };
+
+    const merged = mergeCustomModelsIntoStore(
+      store,
+      new Set(["sisyphus", "hephaestus"]),
+      [],
+      {},
+    );
+
+    expect(merged).toEqual({
+      sisyphus: { model: "builtin-model" },
+      hephaestus: { model: "builtin-model-2" },
+    });
+  });
+
+  it("清空 model 时保留高级字段并移除 model/variant", () => {
+    const store = {
+      sisyphus: { model: "builtin-model" },
+      "custom-agent": {
+        model: "model-a",
+        variant: "fast",
+        temperature: 0.7,
+      },
+    };
+    const customs: CustomModelItem[] = [
+      { key: "custom-agent", model: "", sourceKey: "custom-agent" },
+    ];
+
+    const merged = mergeCustomModelsIntoStore(
+      store,
+      new Set(["sisyphus"]),
+      customs,
+      { "model-a": ["fast"] },
+    );
+
+    expect(merged["custom-agent"]).toEqual({ temperature: 0.7 });
+  });
+});
diff --git a/tests/utils/omoConfig.test.ts b/tests/utils/omoConfig.test.ts
new file mode 100644
index 000000000..5a5de6c91
--- /dev/null
+++ b/tests/utils/omoConfig.test.ts
@@ -0,0 +1,50 @@
+import { describe, expect, it } from "vitest";
+import {
+  mergeOmoConfigPreview,
+  parseOmoOtherFieldsObject,
+  type OmoGlobalConfig,
+} from "@/types/omo";
+
+const EMPTY_GLOBAL: OmoGlobalConfig = {
+  id: "global",
+  disabledAgents: [],
+  disabledMcps: [],
+  disabledHooks: [],
+  disabledSkills: [],
+  updatedAt: "2026-01-01T00:00:00.000Z",
+};
+
+describe("parseOmoOtherFieldsObject", () => {
+  it("解析对象 JSON", () => {
+    expect(parseOmoOtherFieldsObject('{ "foo": 1 }')).toEqual({ foo: 1 });
+  });
+
+  it("数组/字符串返回 undefined", () => {
+    expect(parseOmoOtherFieldsObject('["a"]')).toBeUndefined();
+    expect(parseOmoOtherFieldsObject('"hello"')).toBeUndefined();
+  });
+
+  it("非法 JSON 抛出异常", () => {
+    expect(() => parseOmoOtherFieldsObject("{")).toThrow();
+  });
+});
+
+describe("mergeOmoConfigPreview", () => {
+  it("只合并 otherFields 的对象值，忽略数组", () => {
+    const mergedFromArray = mergeOmoConfigPreview(
+      EMPTY_GLOBAL,
+      {},
+      {},
+      '["a", "b"]',
+    );
+    expect(mergedFromArray).toEqual({});
+
+    const mergedFromObject = mergeOmoConfigPreview(
+      EMPTY_GLOBAL,
+      {},
+      {},
+      '{ "foo": "bar" }',
+    );
+    expect(mergedFromObject).toEqual({ foo: "bar" });
+  });
+});