This paper researched on the atmospheric transmission performance of 0.4μm~0.8μm ray radiation based on the characteristic of the middle latitude atmosphere in China. By analysis of the characteristic of the actual atmosphere, the absorption of molecular and the scattering of the steam and ozone, as well as the aerosol scattering(big granule scattering) are play a leading role to the 0.4μm~0.8μm ray radiation. Then a better atmospheric transmission formula in horizontal path has been deducted. The result of computer simulation indicates that this equation can best calculate the transmission performance of 0.4μm~0·8μm visible radiation in the middle latitude area of China. This computing result was applied to the nuclear explosion parameter detection system based on 0.4μm~0.8μm visible radiation. Through nuclear explosion simulator to produce ray radiation, the tested result indicates that this method has the better measuring precision than the traditional method with the software of LOWTRAN. The calculation result of this formula not only can apply directly to each kind of optoelectronics detecting system, but also to the optical wireless communication system based on the 0.4μm~0.8μm ray radiation.