Multi-missile coordination is a hot research direction of missile weapons with high research value， and how to plan the flight trajectory of multiple missiles is an important research content. In this paper， a multi-ballistic trajectory simulation method based on a multi-objective evolutionary algorithm based on decomposition （MOEA/D） algorithm is proposed， which takes the glide phase of boost glide missile as the research object and aims at planning multiple high-quality trajectories. The maximum range and the maximum final velocity are selected as the objective functions to realize the trajectory planning of the glide phase. Meanwhile， in order to reduce the impact of the initial population on the multi-objective optimization problem， the pseudo-spectral method is used to provide high-quality initial populations for the multi-objective optimization algorithm. The simulation results show that the method can obtain multi-ballistic trajectories with optimal range and final velocity.