To improve the lethality of penetration warhead of air-to-ground missiles a new guidance law of “Trajectory Shaping” was introduced to restrict the missiles impact angle.By comparing the “Trajectory Shaping” with proportional navigation and over-gravity compensation guidance law an mathematic model was established for simulation and the advantages of new guidance law for increasing the missile impact angle were analyzed.The simulation results indicated that the new guidance law can make the missile hit the immobile or maneuvering targets at desired impact angle under the condition at relatively low trajectory and within the maximum acceleration.