Data layering accessing method and system under cloud environment

The present invention relates to a data layering accessing method and system under a cloud environment. The method first establishes system parameters for the provided data, after encrypting the provided data, uploads the same to a cloud data server, and layers the encrypted data stored on the cloud data server, then receives a data request sent by a user, determine whether the request meets a data use permission, and sending a data secret key to the user if so. The technical solution of the present invention solves the problem of distributing layered secret keys with time-limits under the cloud environment, and can provide a relatively safe data access approach under a unsafe cloud storage environment.