Aerogel glass is a high quality product of new building envelope structure, and it can effectively reduce the loss of energy consumption. At present, granular aerogel glass is the main product at home and abroad. In this paper, six kinds of aerogel particles with different particle sizes (6~8 mesh, 8~10 mesh, 10~12 mesh, 12~14 mesh, 14~16 mesh, 16~18 mesh) and four kinds of insulating glass with different filling thicknesses (5.5mm, 6mm, 8mm, 10mm) are selected for compound. The influence of two factors on light transmittance and thermal insulation is studied. The results show that when the particle size of aerogel glass is 8~16 mesh with the same filling thickness, the light transmittance decreases gradually with the particle size decreasing, and the visible light transmittance increases when the particle size is 16~18 mesh. When the filling material is the same, the smaller the filling thickness, the higher the visible light transmittance. By comparing aerogel glass with traditional insulating glass, the light transmittance decreases somewhat and the heat transfer coefficient decreases significantly. Under the light irradiation at 100℃, the thermal insulation effect of aerogel glass gradually increases with the decrease of particle size, and gradually increases with the increase of filling thickness, which is much higher than that of ordinary insulating glass, further confirming its excellent energy-saving effect.