Aiming at the problem that the laser-guided projectile will miss the target due to many random factors, the guidance error of the laser-guided projectile is analyzed. The working process of the laser-guided projectile is given, the mathematical model of the error is established, the influence of the guidance error on the hitting precision is analyzed quantitatively by using the numerical integral algorithm, and the measures to improve the shooting accuracy of the terminal guided projectile are given. The results show that during the shooting process, the illumination error, guidance precision, target size and other factors will directly affect the accuracy of the laser-guided projectile. This study provides a theoretical reference for the operational use of terminal guided projectiles.