diff --git a/src-tauri/src/proxy/forwarder.rs b/src-tauri/src/proxy/forwarder.rs
index 5e562265b..60b1db9a2 100644
--- a/src-tauri/src/proxy/forwarder.rs
+++ b/src-tauri/src/proxy/forwarder.rs
@@ -176,14 +176,24 @@ impl RequestForwarder {
         let mut last_provider = None;
         let mut attempted_providers = 0usize;
 
+        // 单 Provider 场景下跳过熔断器检查（故障转移关闭时）
+        let bypass_circuit_breaker = providers.len() == 1;
+
         // 依次尝试每个供应商
         for provider in providers.iter() {
             // 发起请求前先获取熔断器放行许可（HalfOpen 会占用探测名额）
-            let permit = self
-                .router
-                .allow_provider_request(&provider.id, app_type_str)
-                .await;
-            if !permit.allowed {
+            // 单 Provider 场景下跳过此检查，避免熔断器阻塞所有请求
+            let (allowed, used_half_open_permit) = if bypass_circuit_breaker {
+                (true, false)
+            } else {
+                let permit = self
+                    .router
+                    .allow_provider_request(&provider.id, app_type_str)
+                    .await;
+                (permit.allowed, permit.used_half_open_permit)
+            };
+
+            if !allowed {
                 log::debug!(
                     "[{}] Provider {} 熔断器拒绝本次请求，跳过",
                     app_type_str,
@@ -192,8 +202,6 @@ impl RequestForwarder {
                 continue;
             }
 
-            let used_half_open_permit = permit.used_half_open_permit;
-
             attempted_providers += 1;
 
             log::info!(
@@ -435,10 +443,23 @@ impl RequestForwarder {
             serde_json::to_string_pretty(body).unwrap_or_else(|_| body.to_string())
         );
 
+        // 应用模型映射（独立于格式转换）
+        let (mapped_body, _original_model, mapped_model) =
+            super::model_mapper::apply_model_mapping(body.clone(), provider);
+
+        if let Some(ref mapped) = mapped_model {
+            log::info!(
+                "[{}] >>> 模型映射后的请求 JSON:\n{}",
+                adapter.name(),
+                serde_json::to_string_pretty(&mapped_body).unwrap_or_default()
+            );
+            log::info!("[{}] 模型已映射到: {}", adapter.name(), mapped);
+        }
+
         // 转换请求体（如果需要）
         let request_body = if needs_transform {
             log::info!("[{}] 转换请求格式 (Anthropic → OpenAI)", adapter.name());
-            let transformed = adapter.transform_request(body.clone(), provider)?;
+            let transformed = adapter.transform_request(mapped_body, provider)?;
             log::info!(
                 "[{}] >>> 转换后的请求 JSON:\n{}",
                 adapter.name(),
@@ -446,7 +467,7 @@ impl RequestForwarder {
             );
             transformed
         } else {
-            body.clone()
+            mapped_body
         };
 
         log::info!(
diff --git a/src-tauri/src/proxy/provider_router.rs b/src-tauri/src/proxy/provider_router.rs
index 04eead5f3..dbd1ee008 100644
--- a/src-tauri/src/proxy/provider_router.rs
+++ b/src-tauri/src/proxy/provider_router.rs
@@ -91,29 +91,19 @@ impl ProviderRouter {
                 }
             }
         } else {
-            // 故障转移关闭：仅使用当前供应商
-            log::info!("[{app_type}] Failover disabled, using current provider only");
+            // 故障转移关闭：仅使用当前供应商，跳过熔断器检查
+            // 原因：单 Provider 场景下，熔断器打开会导致所有请求失败，用户体验差
+            log::info!("[{app_type}] Failover disabled, using current provider only (circuit breaker bypassed)");
 
             if let Some(current_id) = self.db.get_current_provider(app_type)? {
                 if let Some(current) = self.db.get_provider_by_id(&current_id, app_type)? {
-                    let circuit_key = format!("{}:{}", app_type, current.id);
-                    let breaker = self.get_or_create_circuit_breaker(&circuit_key).await;
-
-                    if breaker.is_available().await {
-                        log::info!(
-                            "[{}] Current provider available: {} ({})",
-                            app_type,
-                            current.name,
-                            current.id
-                        );
-                        result.push(current);
-                    } else {
-                        log::warn!(
-                            "[{}] Current provider {} circuit breaker open",
-                            app_type,
-                            current.name
-                        );
-                    }
+                    log::info!(
+                        "[{}] Current provider: {} ({})",
+                        app_type,
+                        current.name,
+                        current.id
+                    );
+                    result.push(current);
                 }
             }
         }