The outdoor application of antireflective (AR) films requires not only high transmittance but also mechanical properties such as good abrasion-resistance, and certain AR durability to resist the damage of the harsh environment. In the study, high mechanical performance was achieved by using a binder system in conjunction with the silica nanoparticles (SiO₂-NPs). Hydrogen peroxide (H₂O₂) as a hydroxyl modifier repaired the surface Si–O bonds of SiO₂-NPs effectively. The density of surface hydroxyl groups of the SiO₂-NPs modified with H₂O₂ (H₂O₂–SiO₂-NPs) was boosted from 1.08/nm² to 2.00/nm², providing an effective route to prepare very robust AR films with abundant Si–O–Si bridging chemical bonds. The addition of linear silicate polymers (SiO₂-LPs) into the silica sols performed the function of a polymer binder and markedly improved the abrasion-resistance and AR durability of the films. The H₂O₂–SiO₂-NP/LP composite films derived from these sols possessed excellent optical and mechanical properties. The average transmittance of the composite films reached 97.5% in the visible spectrum, in contrast to 92.0% for a bare glass substrate. Furthermore, the film with a hardness value of 1.7 GPa could pass a 7H pencil test. Moreover, the relationship between structure and properties of the films was discussed considering the formation mechanism.