Some extended range guided projectile trajectory is best designed by this paper, In order to can control projectile flying path, the control phase was separate into sliding phase, accelerating phase and compensation over gravity phase go on research. According to the characteristic of guided projectile sliding phase, the exterior trajectory model was established, then give out a trajectory optimization arithmetic about gliding phase. The arithmetic need not go multifarious grads calculation, the calculation time much lesser to sequence quadratic programming algorithm. The simulation result indicate that the scheme of trajectory not only improve the projectile range, but also advance the projectile hit probability.