Aiming at the problem that the current vehicle communication authentication mechanism lacks hardware verification, this paper proposes a new Vehicle-to-Everything(V2X) user authentication mechanism based on FPGA (Field Programmable Gate Array), aiming at improving the safety and reliability of vehicle communication. The mechanism adopts One-Time Password (OTP), Elliptic curve cryptography (ECC) and Secure Hash Algorithm 2 (SHA-2) to realize a highly secure authentication process, and the above algorithms are implemented in FPGA. Compared with the security and resource cost of using a single cryptography mechanism, this paper is effective in authentication, collision resistance, replay attack, man-in-the-middle attack and identity forgery attack, and completes information encryption processing in microsecond level, which improves the performance and reduces the resource occupation, which proves the security and effectiveness of the proposed method in the case of vehicle-mounted equipment with limited resources.