Taking the limited control authority and guidance information of a gun-launched guided projectile into account, a novel three-dimension terminal guidance law based on the combination of the correction of the velocity direction via impact point prediction and continuous distribution of acceleration command was proposed. The deviations between the impact point of the projectile and the target were predicted on the basis of the series solutions of the nonlinear ballistic equations. According to the deviations, two methods to calculate the direction angle corrections of the current speed were addressed. The remaining flight time was designed as the correction time. The acceleration correction formulas were established through sharing the direction angle corrections of the current speed into the whole remaining guided flight to reduce the possibility of command saturation. By predicting the impact point and distributing the acceleration corrections continuously, the trajectory was shaped in real time. The simulation results show that the proposed guidance law is feasible and effective, and provides the performances of high precision with little requirements of control authority, and has great guidance and damage effects, which can provide reference for the application of the guided projectile.