In order to realize accurate sniping through glass, the trajectory deflection law of projectile penetrating through glass is analyzed by empirical method. Design the acquisition method of ballistic deviation, and obtain the calculation formula of deflection rate and deflection angle through experiment and calculation, and formulate the trajectory correction method of sniper rifle shooting through glass. The results show that this method provides a scientific and feasible technical solution for shooting the enemy and rescuing hostages in street warfare and anti-terrorism operations.