In order to improve the solution accuracy of required velocity and solve the required velocity under the condition that the flight status and target location were uncertain, in this paper, a method based on point of fall for required velocity calculation was presented. In inertial coordinate system, the solving model of required velocity was established, the vertical and horizontal deviations between the object point and the absolute ballistic plane of ballistic missile were revised and the required velocity in current flight state was calculated. The simulation results indicated that this method could effectively solve the required velocity of missile in a certain fligh state with higher accuracy, and the targets could be changed properly.