In order to solve the problem of malicious vehicle nodes attack in VANET system and improve the security of VANET communication, the paper proposes a method of malicious vehicle nodes detection based on repeated games and trust evaluation. First of all, according to vehicle nodes communicating, a repeated game model is established to generate vehicle nodes revenue by punishing attack behavior nodes and rewarding normal behavior nodes. Secondly, a trust evaluation mechanism is introduced to convert vehicle nodes revenue into nodes trust value. Finally, the optimal dynamic threshold is calculated through multiple iterations, comparing and analyzing nodes trust value and dynamic threshold to screen out the malicious vehicle nodes. Simulation experiments show that this mechanism improves the detection rate of malicious nodes and reduces the error detection rate, effectively isolates malicious vehicle nodes according to the change of node trust value, and improves the security of VANET communication.