Data caching method and device

The invention provides a data caching method and device. The method comprises the steps that S1, an IO data block issued from an upper layer is received and split into a plurality of small data blocks; S2, the small data blocks obtained after splitting are made to sequentially access a cache; S3, after access is completed, the small data blocks obtained after splitting are encapsulated into the IOdata block, and the IO data block is submitted to an upper-layer interface through a callback function. The device comprises a data splitting module, a data access module and a data encapsulation module, wherein the data splitting module is used for splitting the IO data block into the small data blocks; the data access module is used for realizing reading or writing access to the cache by the small data blocks; and the data encapsulation module is used for encapsulating the small data blocks into the complete IO data block. By means of splitting the IO data block issued from the upper layerinto smaller data blocks f