Abstract: Aimed at the problem that the broadcast characteristics of vehicular wireless communication and the high mobility of vehicles make it difficult to guarantee the security of the system, a physical layer security transmission mechanism based on artificial noise (AN) and cooperative interference assisted under imperfect channel state information (CSI) is proposed. The first-order Gaussian-Markov process was used to describe the non-ideal CSI caused by high-speed movement of vehicles. The physical layer security of data transmission for legitimate vehicle users was guaranteed through the combination of AN-assisted beamforming and interference noise sent by cooperative vehicles. Considering the impact of non-ideal CSI on the legitimate link transmission and AN leakage, the closed-form expression of the legitimate link security throughput was derived by using stochastic geometry theory, and the system performance was analyzed. The effectiveness of the proposed mechanism was verified by simulations.