1. 确定AWS CDK版本，因为AWS CDK v1和v2有不同的方法来为Lambda函数创建S3触发器。

2. 确认在CDK stack中正确设置了Lambda函数和S3 bucket。

3. 使用以下代码示例为Lambda函数创建S3触发器：

   • AWS CDK v1:

       const lambda = new lambda.Function(this, 'MyLambdaFunction', {
         code: lambda.Code.fromAsset('lambda'),
         handler: 'index.handler',
         runtime: lambda.Runtime.NODEJS_12_X,
       });
     
       const bucket = new s3.Bucket(this, 'MyBucket', {
         bucketName: 'my-bucket-name',
         removalPolicy: cdk.RemovalPolicy.DESTROY,
       });
     
       bucket.addEventNotification(
         s3.EventType.OBJECT_CREATED_PUT,
         new s3n.LambdaDestination(lambda)
       );
     

   • AWS CDK v2:

       const lambda = new lambda.Function(this, 'MyLambdaFunction', {
         code: lambda.Code.fromAsset('lambda'),
         handler: 'index.handler',
         runtime: lambda.Runtime.NODEJS_12_X,
       });
     
       const bucket = new s3.Bucket(this, 'MyBucket', {
         bucketName: 'my-bucket-name',
         removalPolicy: cdk.RemovalPolicy.DESTROY,
       });
     
       bucket.onObjectCreated('MyBucketTrigger', {
         target: new targets.LambdaFunction(lambda),
       });
     

这些代码示例将在CDK stack中为Lambda函数添加对S3对象的触发器。如果仍然无法工作，请检查AWS policy是否正确配置，并确认已经将您的代码推送到AWS Lambda中。