A data transmission system based on PXIe bus and FPGA was designed to realize the acquisition, uploading and analysis of image data in the focusing and leveling system based on linear CCD imaging principle. The system uses FPGA Mezzanine Card (FMC) architecture, composed of mezzanine card and carrier card. The mezzanine card is equipped with four high-speed optical fiber communication interfaces to realize interface interconnection with high-speed image output equipment. The carrier card adopts FPGA as the main controller to receive the image data transmitted by the sandwich card in real time, cache it to the onboard DDR SDRAM, and then transmit it to PC through PXIe interface. After the development of the system, the data transmission performance of the optical fiber interface at the transmission rate of 10Gbps was tested, and the correct and clear track eye diagram was obtained. The batch data transmission test of PXIe interface is carried out, and the results show that the data sent by FPGA is completely consistent with the data received by the host computer, which verifies the correctness and rationality of the scheme.