In order to improve theprecision of downward surface solar radiation product based on the FY-2G visible channel data of geostationary satellite,it is fused by the method of STMAS withthe downward surface solar radiationcalculated by Hybrid,examining and evaluating SWDN and SWDN-MERGE using ground observation data(OBS)from 91 ground observation stations in China(2015),and compared with CERES satellite-derived application and ERA-Interim reanalysis data.The results show that:(1)CERES has the highest precision,FY-2Gfollows,ERA-Interim is the worst.(2)SWDN-MERGE has a greater improvement than SWDN when comparing the two sets of downward surface solar radiation data derived from FY-2Gsatellite.(3)There is good consistency between the four sets of data from the analysis of 2015 year average value,however the surface downward shortwave radiation data derived from FY-2Gsatellite is higher in spatial resolution and sharper in details.The above results could be used as scientific evidences for revising the four sets of data and the study of climate change in China.