Abstract: In this paper, digital elevation model(DEM) data with high spatial resolution and relative sunshine data in some years in mountainous areas were used. The topographic factors of longitude, altitude, slope and aspect, etc. were derived from DEM. With the assistance of GIS technology, the distribution model of direct solar radiation with high spatial resolution was developed to realize the visual expression of the actual spatial distribution of direct solar radiation value. The spatial distribution characteristics of monthly direct solar radiation were analyzed. The research results have great significance to the research fields of agriculture, forestry and ecology in mountainous areas.