Abstract: The heat stimulating is one of the pivotal technology in the active infrared thermal wave non-destructive testing. The extent of uniformity not only affects the quality of thermal-image, and also the magnitude for the temperature-difference, and then affects the last quantitative distinction of defects as well. Therefore, the spatial characteristic, illuminance distribution characteristic of the heat stimulating, and the array of lamps were simulated and investigated by TracePro, The results of the experiments showed that the array of lamps was rebound to advance the illuminance-uniformity, and the veil was good for the uniformity. The paper finally gave some relevant optimized methods, settling the base for the upper hardware design.