CSKH-02.2020. Abstract—With high-speed data transmission such as PCI-Express, the cryptographic intervention in the transmission line, which does not affect the data transmission process but still ensures the data transmission rate of the protocol, will be the foundation to develop cryptographic applications using PCI-Express protocol. In this article, a technical solution to capture the data packet of the PCI-Express protocol using FPGA technology will be presented. Using the standard library of PCI-Express on the computer to connect to the FPGA board, on which organizing the data according to the standard of PCI-Express protocol, at the same time to cryptographic intervening on the line. Thus, plaintext will be transmitted from the computer to the FPGA board via PCI-Express interface, then it will be organized, cryptographic intervened and transmitted back to the computer.