在Lambda函数中添加以下代码，以确保将错误消息发送到SQS DLQ。

import json
import boto3

def lambda_handler(event, context):
    try:
        # Your Lambda function code here
        pass
    except Exception as e:
        sqs = boto3.client('sqs')
        queue_url = 'SQS_DLQ_URL' # Replace with your SQS DLQ URL

        # Send error message to SQS DLQ 
        error_message = {
            'error': str(e),
            'event': event
        }
        response = sqs.send_message(
            QueueUrl=queue_url,
            MessageBody=json.dumps(error_message)
        )
        print(response) # Optional - print SQS response for troubleshooting purposes
        raise e # Rethrow the exception