Abstract: In order to evaluate the importance of the radiation influence between buildings and provide theoretical support for the infrared multispectral simulation method and ATR algorithm research, some research in waveband 3-5 m and 8-12 m was done and a radiation influence calculation model between buildings was built in this paper. When the direct solar radiation existed, it was not necessary to consider the radiation influence between buildings in 3-5 m, because the influence was tiny enough to be ignored, while it should not be ignored in 8-12 m because of the apparent influence. A virtual scene with two cooling towers was build and the radiation in 8 m, 9 m, 10 m, 11 m and 12 m were selected to calculate the radiation influence between the cooling towers. According to the result, the radiation influence in 8 m, 9 m and 10 m is greater than 10%, while that in 11 m and 12 m was smaller. The scene simulation for the radiation influence between the cooling towers is done, which shows the radiation influence at different wavelength with the changes of radiation distance.