The Angstrom-Prescott formula is commonly used in climatological calculation methods of solar radiation simulation. Fitting the coefficients is carried out using linear regression and in recent years it has been found that these coefficients have obvious spatial variability. A common solution is to divide the study area into several subregions and fit the coefficients one by one. Here, we use ground observation data for sunshine hours and solar radiation from 1961 to 2010. Adopting extraterrestrial radiation as the initial value, Angstrom-Prescott coefficients are obtained by Geographically Weighted Regression at a national scale. The surfaces of solar radiation are obtained on the basis of the surfaces of sunshine hours interpolated by high accuracy surface modeling and astronomical radiation; results from spatially nonstationary and error comparison tests show that Angstrom-Prescott coefficients have significant spatial nonstationarity. Compared to existing research methods, the method presented here achieves a better simulation effect.