The embodiment of the invention provides a WPKI (wireless public key infrastructure)-based method and system for realizing data communication security of a cloud storage system. The method mainly comprises the following steps that: the cloud storage system receives a connection request which is transmitted by a user terminal and carries a WPKI digital certificate of a user; after receiving the connection request, the cloud storage system verifies the WPKI digital certificate, and a safe data channel is constructed between the cloud storage system and the user terminal after the WPKI digital certificate passes verification; and data transmission between the cloud storage system and the user terminal can be realized through utilizing the safe data channel. According to the WPKI-based method and system for realizing the data communication security of the cloud storage system of the invention, the security of communication between the user and cloud storage through the intelligent mobile terminal can be guaranteed though adopting the WPKI technologies, and data which are uploaded to the cloud storage system by the user can be protected. The method and system can be used for verifying whether data are tampered, and can be also used as electronic evidences in security audit, and can guarantee data security of cloud storage users.