Evaluating and validating the design scheme of spacecraft trajectory based on formula and chart causes difficulty in understanding and reviewing. Therefore, a simulation strategy of spacecraft real-time maneuver was proposed based on MATLAB and STK. With the missile as research example, the trajectory computing engine was established, which sent the trajectory data to STK in a specific way and at a certain speed. Meanwhile, the trajectory auxiliary display object was created, ensuring the simulation met the real-time and contrast requirement and showed the effect of maneuver. The simulation results show that this strategy can realize real-time maneuver simulation accurately and reliably and can be used for the simulation and verification of spacecraft trajectory design.