The lateral sealing method of vacuum sealing used to fabricate Low-E vacuum glazing. The optical performance and surface morphology of the film at each sealing temperature were tested. The heat transfer rate to the central vacuum glazing was also tested. High-temperature sealing treatment may increase the density of the Low-E film surface. The visible spectral transmittance of the film and the far infrared spectral reflectance were significantly increased, Whereas the near-infrared spectral absorption ratio decreased slightly. The lowest rate of central heat transfer of vacuum glazing was 0.9 W/(m 2 ·K) when the sealing temperature was 500°C. However, above 500°C, after the Ag film breakage and reunion to form a polymer film, the film performance degrades.