<p>Solar radiation in near-earth space significantly influences the formation of the geographical environment, the law of temperature change, and the movement of atmospheric circulation. The present study conducts a comprehensive analysis, including theoretical examination, numerical computation, and analytical investigation, of the spatial and temporal distribution characteristics of solar radiation in the vicinity of the earth. A calculation model for solar radiation in near-earth space is established based on the principles of solar radiation theory and the spatiotemporal relationship between the sun and the earth while ensuring rigorous analysis and verification of its reliability. The research findings suggest that the distribution of solar radiation exhibits latitudinal variations. Compared with the equator, the maximum decrease rates of daily radiation in 60° S and 60° N areas are 93.82% and 93.62% respectively. Furthermore, there exists a maximum difference of 6.9% in annual radiation between symmetric latitudes in the northern and southern hemispheres, indicating an asymmetry in solar radiation distribution. The PSO-SVR algorithm is employed to forecast ground radiation and validate its reliability. The results demonstrate that the PSO-SVR algorithm achieves a fitting degree of 0.91 for predicting ground radiation, indicating high consistency with actual solar radiation received at ground level.</p>