Abstract: Solar irradiance is an important basic parameter for building thermal design,HVAC design and solar energy utilization. At present,Design code for heating ventilation and air conditioning of civil buildings GB 50736—2012 provides the global solar irradiance for summer in the region of 20°-50° north latitude,but there is still a lack of standard values in the low-latitude region below 20° north.To solve this problem,the solar radiation raw data of Yongshu and Xisha,which is at a latitude of 9°40’N and 16°50’N respectively,are organized. Then the processed data are used to calculate fundamental data of solar radiation at a solar elevation of 3° and atmospheric transparency of level 4. Based on the supplemented fundamental data table,through interpolation and theoretical calculation,the global solar irradiance for summer is generated for the area at 10°N and 15°N latitude with atmospheric transparency of level 4. The results provide standard data for the research solar irradiance and application of solar energy in low latitude areas.