In the smoke diffusion model,to calculate the attenuation of electromagnetic wave when it penetrates the smoke cloud along any path,it is necessary to accurately calculate the smoke integral concentration under this path,so as to obtain the transmission rate of electromagnetic wave.Based on the principle of space geometric coordinate transformation,the method of linear algebra matrix operation and the theory of smoke material extinction,the transformation matrix of three-dimensional coordinate system and the projection algorithm of two-dimensional integral concentration are derived when the incident direction of electromagnetic wave changes in the smoke diffusion model.The calculation of integral concentration distribution and transmissivity when the electromagnetic wave incidents in any direction is realized,which lays a foundation for the multi angle(direction) data analysis in smoke diffusion model,infrared image processing of smoke cloud and application in more scenarios.