Provided is a fluorosilicone resin and a preparation method thereof. Using pentafluorostyrene as raw material, pentafluorophenethyldimethylchlorosilane is prepared by a hydrosilylation reaction. By means of a polycondensation reaction of the pentafluorophenethyldimethylchlorosilane, trimethylchlorosilane and tetraethyl orthosilicate, a pentafluorophenyl silicone resin is prepared. The preparation method adopts a two-step polycondensation process, which overcomes the disadvantages of a large difference in hydrolysis reactivity between pentafluorophenyldimethylchlorosilane and a copolymerized trialkyl-chlorosilane, and achieves a high yield. The obtained pentafluorophenyl silicone resin has the advantages of superior heat resistance, simple preparation process, low equipment requirements, high availability of raw material, and suitability for mass production. The heat-resistant fluorosilicone resin can be applied in a polymer material, such as a heat-resistant adhesive.