Abstract: Monte Carlo simulation is used for predicting the radiant heat flux distribution produced by an infrared lamp. To obtain the corresponding empirical heat flux distributions for correlating with analysis, experiments were conducted in KM2 with radiometers, at a low temperature of 100 K and a vacuum environment of 1.3×10-3 Pa, to avoid the influence of air convection. The results show that the difference between the experimental and simulated results is less than 5%, and the simulation results can be used as a basis in the infrared lamp array optimization design.