Abstract: In order to ensure the safety of connected and automated vehicles (CAVs) threatened by cyberattack in the confluence area and mitigate the adverse impact of cyberattack propagation, a framework is built to depict the impact of cyberattacks on traffic operation. Based on this framework, corresponding propagation suppression strategies are proposed for different types of cyberattacks in different periods. Under centralized control, game theory is used to solve the confluence sequence corresponding to the strategies. The results show that the proposed method can effectively inhibit the spread of cyberattacks on the premise of security. The initial control effect is the best. Compared with uncontrolled condition, in the 100 timesteps, 11 susceptible vehicles are finally added, and the second is the immunity period, in which 10 susceptible vehicles were protected from cyberattack. Outbreak and latency control strategies also protect some vehicles. Under the control strategy of each stage, the peak value of infected vehicles and the duration of cyberattack are improved compared with the uncontrolled strategy. In addition, the traffic efficiency in the confluence area is also improved. This method can also be extended to such road types as diverging section, weaving section and intersection, so as to reduce the impact of cyberattacks on road network scale.