In order to grasp the accuracy of solar radiation data from earth system simulation and remote sensing ground object inversion, it is necessary to discuss the regional representation of solar elevation caused by scale effect and the method for determining the data density of solar elevation. The calculation method of average deviation of regional solar elevation is designed and the sample data with reasonable distribution is established. The average deviation of regional solar elevation is calculated with the sample data selected according to the calculation method. Its regular characteristics are summarized according to the established statistical method. According to the statistics, the average deviation of regional solar elevation is substantially correlated with the regional diameter, they are nearly linear relation of positive correlation, and the linear coefficient slightly decreases with the increase of the regional diameter. When the regional diameter is less than 3000 km, the deviation has positive linear relation with the regional diameter with the coefficient of (1.8969-1.9084)×10 ^-3 (°)·km ^-1. The dispersion degree of the average deviation of solar elevation in the region with the same width is very small. The results show that the statistical law is simple, with high stability and high reliability. The scientific evidence is provided for determining the data density of solar elevation in the regional or global earth system simulation and ground object inversion.