The invention provides a safety isolation method for cloud side multi-tenant data storage. According to the safety isolation method for cloud side multi-tenant data storage, isolated distributed storage is applied to multi-tenant data storage, when a tenant applies for a data storage space, storage software API provided by an operator is called, a specific virtual storage area is provided for the tenant through division according to the ID of the tenant, the storage area of each tenant is relatively independent and isolated, and when a tenant uses private data, the distributive storage software collects tenant data from a private space in a disk array on the physical layer according to the ID of the user and provides a data service for the tenant in a concentrated mode; for each tenant, the data isolated distributed storage process is automatically completed by a system, transparent encryption and decryption is conducted on the volume levels, of cloud side multi-tenant data, in the storage disk array on the physical layer, safety isolation of the multi-tenant data in the cloud computing environment is achieved, and the problem that a cloud service provider administrator views, tampers and deletes sensitive data of the tenants without authorization is solved.