A trajectory planning method satisfying multiple constraints is proposed for the off-line trajectory optimization in the gliding phase of interceptor projectiles in near space.First, the gliding motion model is obtained by simplifying the midcourse guidance motion model of the interceptor.Then, by using Pontryagins principle of minimum value, the indirect method model that satisfies multiple constraints is derived, and the trajectory optimization problem is transformed into a two-point boundary value problem of guessing the initial value of co-state variables.The adjacent extreme value method is used to select the initial value of the co-state variable, which reduces the difficulty and calculation amount of initial value guessing.The simulation results show that, compared with proportional guidance ballistics and Gaussian pseudo-spectral ballistics, the proposed ballistics can satisfy terminal constraints and multiple process constraints at the same time, and the optimization results have higher accuracy, which can effectively solve the offline ballistic optimization problem.