There is a good correlation between the monthly average daily total scattered radiation on the horizontal plane and the monthly average daily total solar radiation on the horizontal plane, and between the monthly average daily total solar radiation on the horizontal plane and the monthly average daily total solar radiation on the upper boundary of the earth's atmosphere, so the regression equation of scattered radiation is as follows: =+5.531KT-3.108kt (1). Hd is the monthly average of daily total scattered radiation on the horizontal plane; H is the monthly average daily total solar radiation on the horizontal plane (provided by the Meteorological Observatory); H0 is the daily total monthly average of solar radiation in the upper atmosphere (obtained by table lookup or calculation). Normal direct radiation intensity refers to the direct radiation power per unit area on the plane perpendicular to the radiation direction (the plane facing the sun).