The invention discloses an anti-ultraviolet PET film and a preparation method thereof. The anti-ultraviolet PET film comprises the following raw materials by weight part: PET polyester chip, vinyl organic silicon resin, conductive polymer resin, a silane coupling agent, toluene, butanone, a first ultraviolet absorbent, a second ultraviolet absorbent, an anti-scratch agent, an anti-blocking agent, an oily nano-titanium dioxide dispersion agent, a thioxanthone photoinitiator, glycerol, an antioxidant, and calcium stearate. The anti-ultraviolet PET film provided by the invention has the characteristics of good heat sealability, high heat shrinkage, easy recovery and good mechanical properties, contains ultraviolet absorbents, and can absorb ultraviolet. Also the ultraviolet absorbents are difficult to migrate, thus greatly prolonging the timeliness of the anti-ultraviolet function. The anti-ultraviolet PET film provided by the invention can be used for making anti-ultraviolet heat-insulating film products, can be used for ultraviolet protection of automobiles, constructions and the like, effectively blocks the harmful ultraviolet encountered in daily life, and avoids the damage of ultraviolet to the human body.