A new three-dimensional guidance law with high impact angle constraints used for striking ground moving targets is designed based on back-stepping control approach. The kinematics between the missile and the target are established in line-of-sight (LOS) frame. To ensure the required impact angle and small miss distance, two step controllers are designed based on Lyapunov method. The first step controller guarantees the LOS angle in vertical plane to converge to the desired angle. The second step controller can stabilize the overall system while maintaining minimum LOS rate, and thus the smallest miss distance can be achieved indirectly. Simulation results illustrate the efficiency.