ASV (Low-E film system/SiO2/VO2) and ASVS (Low-E film system/SiO2/VO2) composite film system were prepared on a single silver Low-E glass substrate by magnetron sputtering, and a thermochromic near-infrared isolation film system was obtained. Through UV-NIR spectrophotometer, XPS, XRD and SEM, the effects of VO2 thickness and SiO2 antireflection layer on the permeability and thermal insulation of the film system were studied. The results show that in the range of 20-90 ℃, the near infrared average transmittance Tnir of ASV film system decreases with the increase of temperature, with the increase of VO2 thickness, Tnir decreases, and the selection coefficient Q increases first and then decreases. When the thickness of VO2 is 50 nm, the increment of near-infrared insulation performance ΔTnir at 90 ℃ is 18.56%, and Q is 96.59%. Compared with ASV film system, ASVS film system has 16.88% higher visible light transmittance, while Tnir remains unchanged at 90 ℃, and Q is 102.4%. Its performance is better than ASV film system.