To improve the firing precision of the antiaircraft gun fire control system, aiming at the math model problem of antiaircraft gun firing control system, the filter method and predication model method are researched and the influence of hitting target probability in the antiaircraft gun fire control system is analyzed. Find out the reason of low hitting target probability of filter method and predication model to mobile target. Through analyze dive track features of mobile target (aircraft) and guard target information, put forward the math model of aircraft dive attack, solve the low hitting target probability effectively. Use shooting range flight track data to verify the math model. The result shows that the method can decrease system error and improve predication accuracy to aircraft future point. It is useful to improvement of firing accuracy of antiaircraft gun firing control system.