Data storage method and device and storage system

The invention discloses a data storage method and device and a storage system and belongs to the field of terminal equipment. The data storage method comprises obtaining the data access condition of the current storage engine; determining that the current storage engine comprises data which need to be stored to the next stage of storage engine according to the data access condition of the current storage engine; obtaining the data which need to be stored to the next stage of storage engine; storing the obtained data to the next stage of storage engine and deleting the corresponding data in the current storage engine. The data storage device comprises a first acquisition module, a determination module, a second acquisition module and a data storage module. According to the data storage method and device and the storage system, data storage is performed through a multistage storage engine and accordingly the efficiency of data access is improved, data of the next stage of storage engine are obtained from the cu