A storage emluator comprises a database, for storing job orders and storage data of a storage management system, a stock display unit; a middle piece, for reading the job orders and storage data required by emulation from the storage management system, and transforming into predetermined format to store in a database; a storage system simulation model, with a storage model, a storage device model and a simulation program. The storage emluator has evident intersystem hierarchy, causing system intergration and system function expansion more easy, which is conveniently suitable in a plurality of systems. The invention has excellent reusability, which can be used in different storage management systems only modifying the middle piece, and can be applied in conceptual design of the storage system, daily operation, expansion and improvement and the like.