The invention discloses a preparation method of a
silicon dioxide antireflection film. The preparation method comprises the following steps of preparing a clear
sol by using raw materials like a
silicon compound, a
solvent, a
suppressor, deionized water and acid catalyst under an acidic condition through a
sol-
gel method; stirring and adding aqueous
ammonia and
ethyl acetate into the clear
sol, and reacting for 0.5-24 hours in a 40-100DEG
C constant temperature
backflow condition, so as to prepare milky white
silicon dioxide sol, wherein the milky white
silicon dioxide sol contains 2-10
mass percent of silicon compound, 60-90
mass percent of
solvent and 1-40
mass percent of water; and applying the milky white
silicon dioxide sol onto a substrate with the surface treated, so as to obtain acoating. The
silicon dioxide antireflection coating prepared by the method has higher air
porosity and lower
refractive index, and has much better antireflection effect while maintaining the frictionresistance. The preparation method is low in production cost, slightly affects surrounding environment, and is suitable for large-scale production and application of industry.