Future airspace window shooting system was born to intercept maneuvering targetswhich was designed and constructed by reasonable configuration of the projectile dispersion centre.A new configuration method of projectile dispersion center named spreadingangleequaldividing method was presentedand a corrected formula for calculating the radius of airspace window was also givenwhich solved the problem of low calculation accuracy of existing methods.Simulation example was taken to verify its effect and the simulation result showed that the spreadingangleequaldividing method improves the flatness in airspace window and enlarges its effective areawhich is suitable to configure the projectile dispersion center in future airspace window.