A method, device, and system for controlling a data read/write command in an NVMe over fabric architecture. In the method provided in the embodiments of the present disclosure, a data processing unit receives a control command sent by a control device, the data processing unit divides a storage space of a buffer unit into at least two storage spaces according to the control command sent by the control device, and establishes a correspondence between the at least two storage spaces and command queues, and after receiving a first data read/write command that is in a first command queue and that is sent by the control device, the data processing unit buffers, in a storage space that is of the buffer unit and that is corresponding to the first command queue, data to be transmitted according to the first data read/write command.