Abstract: To obtain the global and diffuse solar radiation in the area without solar radiation observation,a combined model is proposed.Firstly,weather conditions are classified into three types by percentage of sunshine. On this basis,the influence of meteorological environmental factors such as total cloud cover and aerosols on global radiation is explored,and the linear model of the global solar radiation is constructed. Secondly,considering the characteristics of meteorological environmental factors under different weather types,the diffuse fraction and diffuse coefficient models based on Gaussian process regression（GPR）are established to obtain the diffuse radiation. Finally,a combined model of the optimal global and diffuse radiation models is obtained under different weather types. The results show that the model can effectively improve the prediction accuracy of global and diffuse radiation.