diff --git a/crates/oxide_cli/src/main.rs b/crates/oxide_cli/src/main.rs
index c4e19504..d13dbe07 100644
--- a/crates/oxide_cli/src/main.rs
+++ b/crates/oxide_cli/src/main.rs
@@ -470,5 +470,6 @@ fn not_implemented(command: &str) -> ExitCode {
     use ansi_term::Colour::Yellow;
     kernel_info!("command not yet implemented: {}", command);
     eprintln!("{}", Yellow.paint(format!("'{command}' is not yet implemented")));
-    ExitCode::SUCCESS
+    // 2 = 未实现，与 0=成功、1=运行失败区分，供脚本与 CI 识别。
+    ExitCode::from(2)
 }
diff --git a/crates/oxide_cli/tests/cli_smoke.rs b/crates/oxide_cli/tests/cli_smoke.rs
index 537612b7..b8530262 100644
--- a/crates/oxide_cli/tests/cli_smoke.rs
+++ b/crates/oxide_cli/tests/cli_smoke.rs
@@ -63,6 +63,22 @@ fn eval_array_output() {
     assert!(stdout.trim() == "[1, 2, 3]", "eval 数组应打印元素区内容: {stdout}");
 }
 
+#[test]
+fn test_stub_exit_code() {
+    let output = Command::new(env!("CARGO_BIN_EXE_oxide"))
+        .args(["test"])
+        .output()
+        .expect("failed to run oxide test");
+
+    // 未实现子命令固定退出码 2，区别于 0=成功 / 1=运行失败。
+    assert_eq!(output.status.code(), Some(2), "test stub should exit 2");
+    let stderr = String::from_utf8_lossy(&output.stderr);
+    assert!(
+        stderr.contains("not yet implemented"),
+        "test stub should print not-implemented notice: {stderr}"
+    );
+}
+
 #[test]
 fn bench_help() {
     let output = Command::new(env!("CARGO_BIN_EXE_oxide"))