Data access method, device and system

An embodiment of the invention provides a data access method, device and system. The method includes analyzing and preprocessing the next transmission task in a transmission queue while processing a first transmission task in the transmission queue through remote direct memory access RDMA, and transmitting a starting address and the size of the data that the next transmission task corresponds to the last level cache memory LLC to enable the LLC to update the newest copy of the data into the new LLC. When the RDMA processes the next transmission task, the newest copy of the data can be read directly from the LLC, the time expense for accessing the upper layer cache in the transmission process is reduced, the access delay for RDMA to access the memory unit is reduced, and the data transmission performance is improved.