diff --git a/src-tauri/src/services/provider/mod.rs b/src-tauri/src/services/provider/mod.rs
index bc6be2206..2d62d5b0a 100644
--- a/src-tauri/src/services/provider/mod.rs
+++ b/src-tauri/src/services/provider/mod.rs
@@ -206,6 +206,11 @@ impl ProviderService {
                 id
             );
 
+            // 获取新供应商的完整配置（用于更新备份）
+            let provider = providers
+                .get(id)
+                .ok_or_else(|| AppError::Message(format!("供应商 {id} 不存在")))?;
+
             // Update database is_current
             state.db.set_current_provider(app_type.as_str(), id)?;
 
@@ -215,6 +220,14 @@ impl ProviderService {
             // Update local settings for consistency
             crate::settings::set_current_provider(&app_type, Some(id))?;
 
+            // 更新 Live 备份（确保代理关闭时恢复正确的供应商配置）
+            futures::executor::block_on(
+                state
+                    .proxy_service
+                    .update_live_backup_from_provider(app_type.as_str(), provider),
+            )
+            .map_err(|e| AppError::Message(format!("更新 Live 备份失败: {e}")))?;
+
             // Note: No Live config write, no MCP sync
             // The proxy server will route requests to the new provider via is_proxy_target
             return Ok(());
diff --git a/src-tauri/src/services/proxy.rs b/src-tauri/src/services/proxy.rs
index 111154f72..aff8bbc00 100644
--- a/src-tauri/src/services/proxy.rs
+++ b/src-tauri/src/services/proxy.rs
@@ -5,6 +5,7 @@
 use crate::app_config::AppType;
 use crate::config::{get_claude_settings_path, read_json_file, write_json_file};
 use crate::database::Database;
+use crate::provider::Provider;
 use crate::proxy::server::ProxyServer;
 use crate::proxy::types::*;
 use serde_json::{json, Value};
@@ -434,6 +435,49 @@ impl ProxyService {
             .map_err(|e| format!("检查接管状态失败: {e}"))
     }
 
+    /// 从供应商配置更新 Live 备份（用于代理模式下的热切换）
+    ///
+    /// 与 backup_live_configs() 不同，此方法从供应商的 settings_config 生成备份，
+    /// 而不是从 Live 文件读取（因为 Live 文件已被代理接管）。
+    pub async fn update_live_backup_from_provider(
+        &self,
+        app_type: &str,
+        provider: &Provider,
+    ) -> Result<(), String> {
+        let backup_json = match app_type {
+            "claude" => {
+                // Claude: settings_config 直接作为备份
+                serde_json::to_string(&provider.settings_config)
+                    .map_err(|e| format!("序列化 Claude 配置失败: {e}"))?
+            }
+            "codex" => {
+                // Codex: settings_config 包含 {"auth": ..., "config": ...}，直接使用
+                serde_json::to_string(&provider.settings_config)
+                    .map_err(|e| format!("序列化 Codex 配置失败: {e}"))?
+            }
+            "gemini" => {
+                // Gemini: 只提取 env 字段（与原始备份格式一致）
+                // proxy.rs 的 read_gemini_live() 返回 {"env": {...}}
+                let env_backup = if let Some(env) = provider.settings_config.get("env") {
+                    json!({ "env": env })
+                } else {
+                    json!({ "env": {} })
+                };
+                serde_json::to_string(&env_backup)
+                    .map_err(|e| format!("序列化 Gemini 配置失败: {e}"))?
+            }
+            _ => return Err(format!("未知的应用类型: {app_type}")),
+        };
+
+        self.db
+            .save_live_backup(app_type, &backup_json)
+            .await
+            .map_err(|e| format!("更新 {app_type} 备份失败: {e}"))?;
+
+        log::info!("已更新 {app_type} Live 备份（热切换）");
+        Ok(())
+    }
+
     /// 代理模式下切换供应商（热切换，不写 Live）
     pub async fn switch_proxy_target(
         &self,
diff --git a/src-tauri/tests/deeplink_import.rs b/src-tauri/tests/deeplink_import.rs
index 9a349d20a..5a0238c61 100644
--- a/src-tauri/tests/deeplink_import.rs
+++ b/src-tauri/tests/deeplink_import.rs
@@ -1,6 +1,8 @@
 use std::sync::Arc;
 
-use cc_switch_lib::{import_provider_from_deeplink, parse_deeplink_url, AppState, Database, ProxyService};
+use cc_switch_lib::{
+    import_provider_from_deeplink, parse_deeplink_url, AppState, Database, ProxyService,
+};
 
 #[path = "support.rs"]
 mod support;
@@ -17,7 +19,10 @@ fn deeplink_import_claude_provider_persists_to_db() {
 
     let db = Arc::new(Database::memory().expect("create memory db"));
     let proxy_service = ProxyService::new(db.clone());
-    let state = AppState { db: db.clone(), proxy_service };
+    let state = AppState {
+        db: db.clone(),
+        proxy_service,
+    };
 
     let provider_id = import_provider_from_deeplink(&state, request.clone())
         .expect("import provider from deeplink");
@@ -54,7 +59,10 @@ fn deeplink_import_codex_provider_builds_auth_and_config() {
 
     let db = Arc::new(Database::memory().expect("create memory db"));
     let proxy_service = ProxyService::new(db.clone());
-    let state = AppState { db: db.clone(), proxy_service };
+    let state = AppState {
+        db: db.clone(),
+        proxy_service,
+    };
 
     let provider_id = import_provider_from_deeplink(&state, request.clone())
         .expect("import provider from deeplink");
diff --git a/src-tauri/tests/support.rs b/src-tauri/tests/support.rs
index bbe603c44..bc5c8b716 100644
--- a/src-tauri/tests/support.rs
+++ b/src-tauri/tests/support.rs
@@ -1,7 +1,9 @@
 use std::path::{Path, PathBuf};
 use std::sync::{Arc, Mutex, OnceLock};
 
-use cc_switch_lib::{update_settings, AppSettings, AppState, Database, MultiAppConfig, ProxyService};
+use cc_switch_lib::{
+    update_settings, AppSettings, AppState, Database, MultiAppConfig, ProxyService,
+};
 
 /// 为测试设置隔离的 HOME 目录，避免污染真实用户数据。
 pub fn ensure_test_home() -> &'static Path {