The present invention discloses a method for preparing high-performance tread rubber through a filler silylation reaction catalyzed in situ by an ionic liquid. The method is as follow: adding a gum rubber, a filler, a silane and an ionic liquid successively into an open mill or an internal mixer for mixing to obtain a rubber compound; high-temperature remilling the rubber compound; adding a vulcanizing package and an anti-aging agent into the remilled rubber compound at room temperature; and vulcanizing the rubber compound to obtain a vulcanized rubber. The method uses the ionic liquid as a catalyst for the silylation of filler surfaces, which effectively promotes the dispersion of a light-colored filler such as silica in the rubber, and improves the rubber-filler interfacial performance. Therefore, this method can substantially reduce an amount of the silane and improve dynamic mechanical performance of a tread rubber material, including reduced rolling resistance and heat build-up. This method has advantages such as simple technology and no additional processing equipment or step is needed, having an important prospect in preparation of the high-performance tire.