diff --git a/app/api/endpoints/system.py b/app/api/endpoints/system.py
index 739f01d0..d4f0d254 100644
--- a/app/api/endpoints/system.py
+++ b/app/api/endpoints/system.py
@@ -45,6 +45,7 @@ from app.utils.crypto import HashUtils
 from app.utils.http import RequestUtils, AsyncRequestUtils
 from app.utils.security import SecurityUtils
 from app.utils.url import UrlUtils
+from pydantic import BaseModel
 from version import APP_VERSION
 
 router = APIRouter()
@@ -52,6 +53,14 @@ router = APIRouter()
 _NETTEST_REDIRECT_STATUS_CODES = {301, 302, 303, 307, 308}
 
 
+class LlmTestRequest(BaseModel):
+    enabled: Optional[bool] = None
+    provider: Optional[str] = None
+    model: Optional[str] = None
+    api_key: Optional[str] = None
+    base_url: Optional[str] = None
+
+
 def _match_nettest_prefix(url: str, prefix: str) -> bool:
     """
     判断目标URL是否仍然落在允许的协议、主机、端口和路径前缀内。
@@ -276,16 +285,50 @@ def _build_llm_test_data(
     return data
 
 
-def _build_llm_test_snapshot() -> dict[str, Any]:
+def _normalize_llm_test_value(
+    value: Optional[str], *, empty_as_none: bool = False
+) -> Optional[str]:
     """
-    冻结当前 LLM 测试所需配置，避免请求执行过程中被新的保存动作改写。
+    清理来自前端的 LLM 测试字段。
     """
+    if value is None:
+        return None
+    stripped = value.strip()
+    if empty_as_none and not stripped:
+        return None
+    return stripped
+
+
+def _build_llm_test_snapshot(payload: Optional[LlmTestRequest] = None) -> dict[str, Any]:
+    """
+    冻结当前 LLM 测试所需配置。
+
+    优先使用前端传入的临时参数；未传入时回退到已保存配置，兼容旧调用。
+    """
+    provider = settings.LLM_PROVIDER
+    model = settings.LLM_MODEL
+    api_key = settings.LLM_API_KEY
+    base_url = settings.LLM_BASE_URL
+    enabled = bool(settings.AI_AGENT_ENABLE)
+
+    if payload:
+        if payload.enabled is not None:
+            enabled = bool(payload.enabled)
+        if payload.provider is not None:
+            provider = _normalize_llm_test_value(payload.provider) or ""
+        if payload.model is not None:
+            model = _normalize_llm_test_value(payload.model) or ""
+        if payload.api_key is not None:
+            api_key = _normalize_llm_test_value(payload.api_key, empty_as_none=True)
+        if payload.base_url is not None:
+            base_url = _normalize_llm_test_value(payload.base_url, empty_as_none=True)
+
     return {
-        "enabled": bool(settings.AI_AGENT_ENABLE),
-        "provider": settings.LLM_PROVIDER,
-        "model": settings.LLM_MODEL,
-        "api_key": settings.LLM_API_KEY,
-        "base_url": settings.LLM_BASE_URL,
+        "enabled": enabled,
+        "provider": provider,
+        "model": model,
+        "api_key": api_key,
+        "base_url": base_url,
     }
 
 
@@ -679,11 +722,14 @@ async def get_llm_models(
 
 
 @router.post("/llm-test", summary="测试LLM调用", response_model=schemas.Response)
-async def llm_test(_: User = Depends(get_current_active_superuser_async)):
+async def llm_test(
+    payload: Annotated[Optional[LlmTestRequest], Body()] = None,
+    _: User = Depends(get_current_active_superuser_async),
+):
     """
-    使用当前已保存配置执行一次最小 LLM 调用。
+    使用传入配置或当前已保存配置执行一次最小 LLM 调用。
     """
-    snapshot = _build_llm_test_snapshot()
+    snapshot = _build_llm_test_snapshot(payload)
     data = _build_llm_test_data(
         provider=snapshot["provider"],
         model=snapshot["model"],
diff --git a/tests/test_system_llm_test.py b/tests/test_system_llm_test.py
index 792116fb..e185cc34 100644
--- a/tests/test_system_llm_test.py
+++ b/tests/test_system_llm_test.py
@@ -142,6 +142,47 @@ class LlmTestEndpointTest(unittest.TestCase):
         self.assertEqual(resp.data["duration_ms"], 321)
         self.assertEqual(resp.data["reply_preview"], "OK")
 
+    def test_llm_test_prefers_request_payload_over_saved_settings(self):
+        llm_test_mock = AsyncMock(
+            return_value={
+                "provider": "openai",
+                "model": "gpt-4.1-mini",
+                "duration_ms": 123,
+                "reply_preview": "OK",
+            }
+        )
+        payload = system_endpoint.LlmTestRequest(
+            enabled=True,
+            provider="openai",
+            model="gpt-4.1-mini",
+            api_key="sk-live",
+            base_url="https://example.com/v1",
+        )
+
+        with patch.object(system_endpoint.settings, "AI_AGENT_ENABLE", False), patch.object(
+            system_endpoint.settings, "LLM_PROVIDER", "deepseek"
+        ), patch.object(system_endpoint.settings, "LLM_MODEL", "deepseek-chat"), patch.object(
+            system_endpoint.settings, "LLM_API_KEY", "sk-saved"
+        ), patch.object(
+            system_endpoint.settings, "LLM_BASE_URL", "https://api.deepseek.com"
+        ), patch.object(
+            system_endpoint.LLMHelper,
+            "test_current_settings",
+            llm_test_mock,
+            create=True,
+        ):
+            resp = asyncio.run(system_endpoint.llm_test(payload=payload, _="token"))
+
+        llm_test_mock.assert_awaited_once_with(
+            provider="openai",
+            model="gpt-4.1-mini",
+            api_key="sk-live",
+            base_url="https://example.com/v1",
+        )
+        self.assertTrue(resp.success)
+        self.assertEqual(resp.data["provider"], "openai")
+        self.assertEqual(resp.data["model"], "gpt-4.1-mini")
+
     def test_llm_test_rejects_empty_reply(self):
         with patch.object(system_endpoint.settings, "AI_AGENT_ENABLE", True), patch.object(
             system_endpoint.settings, "LLM_PROVIDER", "deepseek"