Aiming at the shortcoming that base-catalyzed quarter-wave silica antireflective coatings, prepared by sol-gel method, are porous and therefore low environment-resistant, water/NH3 vapor and/or hexamethyldisilazane vapor were utilized to modify the surface of these coatings to obtain high hydrophobicity and abrasion-resistance. Otherwise, comparison between different modified results from single vapor and combined vapors, were carried out to show the changes of coatings’ physical properties and microstructures after different surface modifications and the influence of the treated order of combined vapors to the result coatings. According to the investigations, some conclusion can be drawn that water-ammonia vapor treatment facilitates the cross-link between hydroxyl groups in coatings, which reduces the film thickness, strengthens the abrasion-resistance, and simultaneously maintains the high transmittance; hexamethyldisilazane vapor treatment introduces methyl groups into coatings, making the polarity of coating surface and the interaction between particles decreased obviously, leading to poorer abrasion-resistance but fortunately, distinctly improved hydrophobicity; when coatings are treated by water-ammonia combined hexamethyldisilazane vapor, the water-ammonia vapor firstly strengthens the abrasion-resistance and meanwhile reduces the amount of hydroxyl groups which hindered the later hexamethyldisilazane vapor treatment, finally obtaining AR coatings with good abrasion-resistance and a certain extent of hydrophobicity; when coatings are treated by hexamethyldisilazane combined water-ammonia vapor, the hexamethyldisilazane vapor obviously improves the hydrophobicity but weakens the effect of water-ammonia vapor, resulting in a slight weaker abrasion-resistance compared to that after single water-ammonia vapor treatment.