diff --git a/service/exec/exec.go b/service/exec/exec.go
index a267275..1192b3d 100644
--- a/service/exec/exec.go
+++ b/service/exec/exec.go
@@ -80,6 +80,9 @@ func NewDockerContainer(memory int64, cpu int64) (*dockerContainer, error) {
 // CreateAndStartContainer creates a container, sets resource limits, and starts it
 // The container runs `tail -f /dev/null` to keep running, waiting for new commands
 func (dc *dockerContainer) CreateAndStartContainer() error {
+	if dc == nil {
+		return fmt.Errorf("no container found, please create and start the container first")
+	}
 	// 如果容器已经存在，则跳过创建
 	if dc.ContainerID != "" {
 		fmt.Println("Container already exists, skipping creation.")
@@ -131,7 +134,7 @@ func (dc *dockerContainer) CreateAndStartContainer() error {
 
 // ExecCommandInContainer executes a command in the existing container and returns its output
 func (dc *dockerContainer) ExecCommandInContainer(command string) (string, error) {
-	if dc.ContainerID == "" {
+	if dc == nil {
 		return "", fmt.Errorf("no container found, please create and start the container first")
 	}
 
@@ -173,6 +176,9 @@ func (dc *dockerContainer) ExecCommandInContainer(command string) (string, error
 
 // RestartAndCleanContainer stops, removes, and recreates the container
 func (dc *dockerContainer) RestartAndCleanContainer() error {
+	if dc == nil {
+		return nil
+	}
 	if dc.ContainerID == "" {
 		return fmt.Errorf("no container to restart")
 	}
@@ -218,6 +224,9 @@ func (dc *dockerContainer) RestartAndCleanContainer() error {
 
 // RemoveContainer stops and removes the container
 func (dc *dockerContainer) RemoveContainer() error {
+	if dc == nil {
+		return nil
+	}
 	if dc.ContainerID == "" {
 		return fmt.Errorf("no container to remove")
 	}