Abstract: To learn more about sunken solar greenhouse insulation performance, the air temperature field inside sunken solar greenhouse with cover curtain was simulated using computational fluid dynamics (CFD)based on unsteady heat transfer model in sunlight greenhouse, and experiment was conducted to validate the simulated results. The validation results showed that simulated results of CFD about air temperature field with cover curtain had a higher reliability. In order to improve heat preservation rate of sunken solar greenhouse, its air temperature field under different cover curtain time was simulated using CFD software and effect on heat energy distribution was analyzed. The results showed that effect of different cover curtain time on air temperature at night inside sunken solar greenhouse was significant, under the conditions of low light and large air temperature difference of inside and outside greenhouse afternoon, night-time air temperature could be significantly improved by cover curtain earlier. This study can provide a more reference for the CFD application and cover curtain management in sunken solar greenhouse.