Abstract: Aiming at such shortcomings of man-made space launch plan as small solution scale, slow solution speed, high adjustment cost and difficult to obtain the optimal solution, an automatic launch plan generation method based on improved simulated annealing algorithm is proposed. Firstly, the research objects and constraints of space launch plan are analyzed, the objective function of mission plan is constructed, and the optimization mathematical model is established. Then, the simulated annealing algorithm is introduced to improve the new solution generation mechanism and to improve the iterative search efficiency. Finally, through the test and analysis of an example, it shows that this method has fast solution speed and good optimization effect, and can significantly improve the arrangement efficiency of space launch plan.