In order to meet the demand of real-time and high-bandwidth data transmission between aerospace equipment and computer, a high-speed data transmission system based on PCI 3.0 bus interface was designed.The data was collected by reading board and then transmitted to host computer in short burst or continuous mode.The design adopts the Scatter-gather Direct Memory Access (SG-DMA) data transmission mode, compared with the traditional Block DMA, reduces the utilization of CPU resources, reduces the interruption time of DMA, and improves the overall performance of the system.Through the upper computer program developed by Qt Creator platform, the write bandwidth and read bandwidth of PCIe can reach 4698MB/s and 4797MB/s in the upper computer software interface, and the average bus utilization rate of PCIe is as high as 58.86%, which can fully meet the demand for high-bandwidth data transmission in the project.