In view of the complexity of node selection and migration at platform dynamic defense, a single stage static game strategy is designed based on the system prior information. Through analyzing from the principle of dynamic platform defense, a single stage static game model is constructed by combining the needs of the defense under conditions of game relationship between the two parties and complete information condition, and a process of the key parameters of the attack and defense utility and the complete information game is proposed. The demo and the simulation results show that after 1000 times of attack-defense game experiments, the actual revenue of the defense is , and the actual revenue of the attacker is , showing that the proposed strategy can effectively intercept cyber attacks, and the expected revenue of the defense is , the deviation between the actual revenue and the expected revenue is about 1.8%. The revenue of the new strategy is much higher than that of the undifferentiated migration strategy. The single-stage static game strategy based on the system prior information can solve the problems of high cost, unbalanced defense budget and effective node migration in the traditional platform dynamic defense.