Aiming at the problem of how the attacking missile strikes the ground target effectivelywhich defends the attacking missile by launching defensive missilea three-body game engagement kinematics model is establishedan objective function integrating miss distance and required acceleration is constructed and a differential game guidance law considering first-order kinetics autopilot is proposed.On the premise of three-point guidance and interception of defense missilethe guidance strategies of proportional guidance and differential game guidance of attack missile are simulated and verified respectively.Finallythe effectiveness of the proposed method is proved by analyzing acceleration constraints and terminal conditions.