Based on the solar irradiation observational data at 3 stations in Fushan, Jinan and Juxian in Shandong province, and by setting up five solar irradiation simulation schemes combining MODIS aerosol optical thickness (AOD550 nm) data in Shandong area, the simulation performance of WRF-Solar numerical model is analyzed, which can be specially applied to solar resource assessment and applications in different area, different time periods for sunny, cloudy and rainy days, and for months representative of four seasons. The results show that the simulations of solar irradiation are best in sunny and partly cloudy days, and not so good in cloudy and rainy days. The simulations are best in Autumn and Winter when there are less cloudy and rainy days, the secondary is in Spring, and the worst in Summer. The simulations of solar irradiation in sunny days and partly cloudy days are best while using the Rapid Radiative Transfer Model for Global Circulation Models (RRTMG) scheme for longwave and shortwave radiation, Grell 3D ensemble scheme for cumulus parametrization and the MODIS aerosol optical thickness (AOD550 nm) data in WRF-Solar numerical model being considered. The simulations of solar irradiation in all days in months representative of four seasons, regardless of synoptic processes, are best by using the new Goddard scheme for longwave and shortwave radiation, the Grell 3D ensemble scheme for cumulus parametrization and the AOD550 nm data. The simulation effect of solar irradiation in sunny days is improved by adding the AOD550 nm data, but the improvements are not obvious on cloudy and rainy days in Autumn and Winter. In addition, the simulation effect of solar irradiation in low visibility days is improved by adding the AOD550 nm data.