diff --git a/backend/src/main.rs b/backend/src/main.rs
index 26d80e8..d62b413 100644
--- a/backend/src/main.rs
+++ b/backend/src/main.rs
@@ -15,7 +15,24 @@ use axum::middleware;
 
 #[tokio::main]
 async fn main() -> anyhow::Result<()> {
-    dotenvy::dotenv().ok();
+    // 增强：支持通过 ENV_FILE 指定要加载的环境文件
+    // - ENV_FILE=prod 或 production => .env.prod
+    // - ENV_FILE=dev 或 development => .env
+    // - ENV_FILE=staging => .env.staging
+    // - ENV_FILE=任意字符串 => 视为显式文件名或路径
+    if let Ok(v) = std::env::var("ENV_FILE") {
+        let filename = match v.trim() {
+            "" => ".env".to_string(),
+            "prod" | "production" => ".env.prod".to_string(),
+            "dev" | "development" => ".env".to_string(),
+            "staging" | "pre" | "preprod" | "pre-production" => ".env.staging".to_string(),
+            other => other.to_string(),
+        };
+        dotenvy::from_filename(&filename).ok();
+    } else {
+        dotenvy::dotenv().ok();
+    }
+
     tracing_subscriber::fmt().with_env_filter(tracing_subscriber::EnvFilter::from_default_env()).init();
 
     let db = db::init_db().await?;