Aiming at the impact point prediction of one-dimensional modified projectile exterior trajectory, an improved perturbation impact point prediction algorithm is proposed. A 6-DOF rigid trajectory model is established, and the aerodynamic simulation of one-dimensional correction projectile is carried out. The mapping relationship between aerodynamic parameters of projectile and Mach number and angle of attack is deduced, and the trajectory simulation is carried out. The trajectory application algorithm is used to predict the impact point. The algorithm constructs the predicted partial derivative according to the upper and lower disturbance trajectories of the relative reference trajectory and calculates the impact point error at the same time, and averages the predicted impact point error to improve the prediction accuracy. The optimal correction time is determined through the mapping relationship between the working range and the correction distance of the off-line resistance mechanism. Under the condition of various error interferences, the simulation results verify the effectiveness of the algorithm for correcting the statistical parameters of ballistic impact point and evaluating the statistical parameters of impact point. A Monte Carlo trajectory simulation system, which consists of trajectory simulation, pneumatic simulation, impact point prediction and trajectory correction, is constructed to simulate the firing process of non-controlled and controlled correction projectiles.