This article aimed at establishing the simulation methods of heat flux distribution and optimization for infrared lamp array to improve the uniformity of heat flux distribution.The heat flux distribution database was generated by the application of heat flux distribution calculating method of single lamp.The reflex heat flux of reflective baffles was resolved.The infrared lamp array heat flux simulation method was established on the basis of these models.Optimization method of infrared lamp array was set up based on genetic algorithm.One infrared lamp array for a satellite thermal test was optimized,and the heat flux nonuniformity decreased from 24.61% to 8.96%.The simulation results were identical with the measurement values.The simulation method offers a good accuracy and the optimization method can effectively increase the uniformity.