Embodiments of the present invention provide a data processing system and a data processing method. An MMIO address of a data request is obtained, where data stored in a PCIe storage device can be directly obtained from the MMIO address, and according to the MMIO address, a network adapter can directly read the data from the PCIe storage device of the data processing system, and transmit the data to a second data processing system, or directly write the data received from the second data processing system into the PCIe storage device. Therefore, the processing system can implement transmitting data directly from the PCIe storage device to the network adapter without using memory. During data transmission between the two data processing systems, a usage ratio of a resource, such as memory and a CPU, is reduced, and efficiency of data transmission is improved.