Abstract: Since connected automated vehicles are vulnerable to cyberattacks in an open communication environment, a security control method was proposed to ensure the safe driving behavior of vehicles under cyberattacks. The system architecture was first designed, which integrated detection and repair mechanisms. Then, an anomaly detection method based on the threshold of vehicle dynamics parameters and a double-stranded repair based on the DNA double helix structure were presented specifically. Through the anomaly detection method, the rationality of the vehicle dynamics parameters such as acceleration, speed, and displacement was derived; if the parameters' values are abnormal, the repair mechanism worked and repaired the abnormality to stabilize the vehicle driving behavior. To verify the effectiveness of the proposed method, a series of simulations were conducted, where three scenarios were discussed, i.e., no detection mechanism, detection mechanism, and detection mechanism failure. Simulation results show that cyberattacks can influence vehicles' behaviors, and the proposed safety control method can relieve or resist the impact of cyberattacks effectively. The research results will provide a scientific basis for designing security schemes and keeping the platoons run safely and stably.