diff --git a/docs/technical/API_SERVER_EXTERNAL_SERVICE_ENV_CONFIG_2026-05-07.md b/docs/technical/API_SERVER_EXTERNAL_SERVICE_ENV_CONFIG_2026-05-07.md
index a89274c3..10927240 100644
--- a/docs/technical/API_SERVER_EXTERNAL_SERVICE_ENV_CONFIG_2026-05-07.md
+++ b/docs/technical/API_SERVER_EXTERNAL_SERVICE_ENV_CONFIG_2026-05-07.md
@@ -74,6 +74,7 @@ ARK_CHARACTER_VIDEO_MODEL / DASHSCOPE_CHARACTER_VIDEO_MODEL
 3. 文本 LLM provider 为 `ark` 且未配置 `GENARRATIVE_LLM_BASE_URL` 时，仍回退到 Ark 公开基础 URL。
 4. 角色视频 provider 复用 Ark 且未配置 `ARK_CHARACTER_VIDEO_BASE_URL` 时，仍回退到 Ark 公开基础 URL。
 5. 具体模型名缺失时不在配置层伪造默认模型，调用到对应能力时由下游配置校验返回缺配置错误。
+6. 本地开发启动脚本与 Rust 入口会按 `.env` → `.env.local` → `.env.secrets.local` 逐级覆盖本地变量；`.env.secrets.local` 作为最后一级，会覆盖前两者同名变量。
 
 ## 示例文件
 
diff --git a/scripts/api-server-dev.mjs b/scripts/api-server-dev.mjs
index c90de96f..20e9c6e4 100644
--- a/scripts/api-server-dev.mjs
+++ b/scripts/api-server-dev.mjs
@@ -8,7 +8,7 @@ const apiServerExePath = resolve(
   'server-rs/target/debug/api-server.exe',
 );
 
-function loadEnvFile(path, target) {
+function loadEnvFile(path, target, override = false) {
   if (!existsSync(path)) {
     return;
   }
@@ -26,7 +26,7 @@ function loadEnvFile(path, target) {
     }
 
     const [, key, rawValue] = match;
-    if (target[key] !== undefined) {
+    if (!override && target[key] !== undefined) {
       continue;
     }
 
@@ -36,8 +36,8 @@ function loadEnvFile(path, target) {
 
 const mergedEnv = { ...process.env };
 loadEnvFile(resolve(repoRoot, '.env'), mergedEnv);
-loadEnvFile(resolve(repoRoot, '.env.local'), mergedEnv);
-loadEnvFile(resolve(repoRoot, '.env.secrets.local'), mergedEnv);
+loadEnvFile(resolve(repoRoot, '.env.local'), mergedEnv, true);
+loadEnvFile(resolve(repoRoot, '.env.secrets.local'), mergedEnv, true);
 
 mergedEnv.GENARRATIVE_API_HOST = mergedEnv.GENARRATIVE_API_HOST || '127.0.0.1';
 mergedEnv.GENARRATIVE_API_PORT = mergedEnv.GENARRATIVE_API_PORT || '3100';
diff --git a/server-rs/crates/api-server/src/llm.rs b/server-rs/crates/api-server/src/llm.rs
index c4944c6b..7d359e3e 100644
--- a/server-rs/crates/api-server/src/llm.rs
+++ b/server-rs/crates/api-server/src/llm.rs
@@ -192,6 +192,7 @@ mod tests {
         let state = seed_authenticated_state(AppConfig {
             llm_base_url: server_url,
             llm_api_key: Some("test-key".to_string()),
+            llm_model: "ark-router-test".to_string(),
             ..AppConfig::default()
         })
         .await;
@@ -267,6 +268,7 @@ mod tests {
         let state = seed_authenticated_state(AppConfig {
             llm_base_url: server_url,
             llm_api_key: Some("test-key".to_string()),
+            llm_model: "ark-router-test".to_string(),
             ..AppConfig::default()
         })
         .await;
diff --git a/server-rs/crates/api-server/src/main.rs b/server-rs/crates/api-server/src/main.rs
index 96d76558..ff5e8a8c 100644
--- a/server-rs/crates/api-server/src/main.rs
+++ b/server-rs/crates/api-server/src/main.rs
@@ -99,10 +99,10 @@ fn run_api_server_with_runtime() -> Result<(), std::io::Error> {
 }
 
 async fn run_api_server() -> Result<(), std::io::Error> {
-    // 运行本地开发与联调时，优先从仓库根目录加载本地变量，避免手工逐项导出 OSS / APIMart 配置。
+    // 运行本地开发与联调时，按 .env -> .env.local -> .env.secrets.local 逐级覆盖本地变量。
     let _ = dotenvy::from_filename(".env");
-    let _ = dotenvy::from_filename(".env.local");
-    let _ = dotenvy::from_filename(".env.secrets.local");
+    let _ = dotenvy::from_filename_override(".env.local");
+    let _ = dotenvy::from_filename_override(".env.secrets.local");
 
     // 统一先从配置对象读取监听地址，避免后续把环境变量读取散落到入口和路由层。
     let config = AppConfig::from_env();