With the rapid development of information technology, cloud computing has become increasingly popular, attracting a large number of users to outsource personal or corporate data to the cloud for storage and management. However, with the growth of data outsourced to the cloud, issues of data integrity and security have become increasingly prominent. These issues have become a focus of concern for both users and cloud service providers. We propose a novel auditing scheme for multi-cloud multi-replica storage. This scheme leverages a cloud combiner for coordination. Additionally, we design a bit-map-based file storage mapping mechanism. This scheme can audit multiple replicas of files stored on different cloud servers and provide feedback on the integrity and storage locations of the corresponding replica files. Therefore, the proposed scheme can enhance data security and auditing efficiency in a multi-cloud environment. Security analysis and performance evaluation both indicate that the scheme provides reliable and efficient auditing for outsourced data in a multi-cloud setting.