The invention discloses an antireflective polymer composite film with atomic oxygen erosion resistance, comprising a polymer film layer and an organic-inorganic composite layer with embedded hollow SiO2 nanoparticles; the hollow SiO2 nanoparticles are embedded evenly in at least one side of the polymer film layer, and the organic-inorganic composite layer with embedded hollow SiO2 nanoparticles is formed on the surface of the polymer film layer. A preparation method of the polymer composite film is also disclosed; the preparation method comprises: preparing a hollow SiO2 nanoparticle layer and a polymer film layer on a rigid base, peeling off the rigid base after solidifying to obtain a polymer composite film with hollow SiO2 nanoparticles embedded in its single side; the polymer composite film with hollow SiO2 nanoparticles embedded in its single side can be further prepared into a polymer composite film with hollow SiO2 nanoparticles embedded in its both sides. The polymer composite film prepared herein can provide both antireflective property and atomic oxygen erosion resistance, and the preparative operations are simple.