A thermochromic film was prepared with VO₂@SiO₂ core-shell nanoparticles to enhance the visible light transmittance and weather resistance of thermochromic film and also decrease the agglomeration of VO₂ nanoparticles prepared by thermal decomposition method. VO（OH）₂@SiO₂ core-shell nanoparticles were prepared by coating SiO₂ layer on the surface of VO（OH）₂ nanoparticles via the surface electric interaction between nagatively charged VO（OH）₂ nanoparticles and positively charged NH₂ groups of aminopropyltriethoxylsilane. Then a normal heat treatment of VO（OH）₂@SiO₂ under Ar atmosphere was utilized to obtain VO₂@SiO₂ nanoparticles. Subsequently optical film with good thermochromic property was prepared by coating the resin dispersion of VO₂@SiO₂ on well cleaned glass. The thermochromic property and the weather resistance of thermochromic film were studied . From TEM images， we find that SiO₂ shell prevents the agglomeration of VO（OH）₂ during heat treatment. Research on the optical properties of the film shows that the SiO₂ and air of low refractive index can improve the optical properties of thermochromic films，and when the mass fraction of VO₂@SiO₂ nanoparticles is 10wt%， the optical performance of the composite film is the best. The protective effect of the SiO₂ shell to the VO₂ core obviously improves the oxidation resistance and corrosion resistance of VO₂ in damp heating and acidic environment， which makes longer life of VO₂ thermochromic film.