NOVELTY - Trifunctional coating film is prepared by assembling large silica nanoparticles on glass substrate to form functional coating film microstructure layer; adding porogenic agent to control space filling factor; assembling upper fluorinated silica nanogranules; constructing double-level rough surface coating film with overhanging structures; and reducing surface free energy by fluoride.    USE - Trifunctional coating film used for optoelectronic components, solar cells, or laser systems.    ADVANTAGE - The trifunctional coating film has super hydrophobic and oleophobic high transmittance property; and exhibits frost, fog, and anti-pollution resistance. It has antibacterial and self-cleaning properties, has excellent light transmittance, and can effectively protect optical components in harsh environments, thus ensuring operational reliability and long life of optical components.    DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for preparation of trifunctional coating film by mixing 98 wt.% concentrated sulfuric acid and 30 wt.% aqueous hydrogen peroxide solution at volume ratio of 3:1; soaking glass substrate into solution for 5 minutes; ultrasonic washing with deionized water and acetone for 20 minutes; treating glass substrate with 5mol/l sodium hydroxide solution at room temperature for 5 minutes; drying at room temperature to obtain activated glass substrate; mixing tetraethyl orthosilicate and dimethyl diethoxysilane at volume ratio of 2:1 to obtain mixed solution; adding 3 ml mixed solution with 25 ml anhydrous alcohol; uniformly mixing to obtain solution A; adding 25 wt.% of 3-5 ml concentrated ammonia with 25 ml ethanol; uniformly stirring to obtain solution B; slowly dropping solution B into solution A; mixing for 1-2 hours to obtain mixed sol solution; adding mixed sol solution with porogenic agent and dimethyl diethoxysilane at mass ratio of 3:1; stirring for 30 minutes; aging for 48 hours; diluting with absolute ethanol at volume ratio of 1:1; uniformly mixing to obtain lower layer dip coating liquid; immersing activated glass substrate into dip coating liquid at 50 mm/minute for 15 minutes; further dip coating at 200 mm/minute for 1 hour; taking out and drying glass substrate at 50 degrees C; calcining at 500 degrees C for 1-2 hours to obtain lower layer coated film; mixing tetraethylorthosilicate and dimethyl diethoxysilane according to volume ratio of 2:1 to obtain mixed liquid; adding 2 ml of mixed liquid with 60 ml ethanol; uniformly stirring; adding fluorosilane compound based on dimethyl diethoxysilane and fluorosilane compound molar ratio of 17:3; uniformly mixing to obtain mixed silane solution; dropping 1-1.5 ml of 25 wt.% concentrated ammonia; stirring at room temperature for 1-2 hours; aging for 48 hours; diluting with ethanol at volume ratio of 1:1; uniformly stirring to obtain upper layer dip coating liquid; immersing layer coated film into upper layer dip coating liquid at 50 mm/minute for 15 minutes; further dip coating at 200 mm/minute for 1 hour; drying at 50 degrees C; and heat treating at 110 degrees C for 1-2 hours to obtain super hydrophobic and oleophobic high transmittance trifunctional coating film.