A storage array, a storage system, and a data access method. A data access method of a storage device includes: transferring data input from a user interface chip to a non-volatile storage device through a peripheral component interconnect express (PCIE) link, where the user interface chip and the non-volatile storage device are connected to the PCIE link, and the non-volatile storage device includes a memory and a non-volatile storage medium; writing the data to the memory of the non-volatile storage device; and writing the data written in the memory of the non-volatile storage device to the non-volatile storage medium. The technical solutions provided by the embodiments of the present disclosure are advantageous for reducing occupation of PCIE links due to data access and improving system performance.