In this paper aimed at the application problem of certain aviation bomb for a certain fighter, a coincidental calculation method of bomb ballistic coefficient is proposed. In the method particle trajectory model of certain aviation bomb is chosen, drag law by the numerical simulation based on the virtual wind - tunnel is adopted. Combined with the ball firing data, the coincidental ballistic coefficient is calculated. The range error based on the coincidental calculation method does not exceed 1%, the method is effective and also applicable to other non-control aviation bombs.In this research, the other particle trajectory models are also available.The more the trajectory model and drag law are consistent with those in the fire control computer, the more the trajectory characteristic parameter is of practical value. Considering aviation rocket or bullet, Siacci drag law could be adopted. With regard to aviation scatter bomb and low altitude high-drag parachute bomb, the corresponding characteristic parameter of equivalent trajectory could be obtained.