Abstract: In this paper, a method using sparse infrared lamp array was proposed to simulate the external space heat flux for batch production satellites. Firstly, numerical analysis was conducted based on the physical characteristics and the heat flux simulation requirements of 13169X/98 infrared lamp to obtain the plane heat flux distribution pattern. Then, a test was conducted in a vacuum facility to calibrate and verify the accuracy of the numerical calculation, and the heat flux distribution characteristics of infrared lamp were summarized. By comparing different temperature control methods, the optimal method matching the output characteristics of the infrared lamp array was selected out to realize a heat flux stability of less than 3 W/m². Finally, with the constraint condition of heat flux non-uniformity causing a temperature gradient of less than 3 ℃ on the surface of satellite cabin, the number and layout of sparse infrared lamp arrays were optimized. The results show that the deviation of heat flux simulation can be less than 3% with a lamp coverage coefficient of less than 5%, which indicates that the simulation of almost uniform external heat flux can be achieved with fewer lamps.