The invention discloses a synthesis method of vinyl triisoacryloyloxy silane. The method comprises the steps that S1, anhydrous treatment is carried out on preparation raw materials and equipment of vinyl triisoacryloyloxy silane; S2, acetone, benzene, triethylamine and cuprous chloride in the raw materials subjected to anhydrous treatment in S1 are directly placed in a reaction tank, and the mixture is heated and stirred; S3, then the raw material, namely vinyl trichlorosilane is preheated, vinyl trichlorosilane is conveyed into the reaction tank in S2 at a constant speed by using a feeding device, and after vinyl trichlorosilane is added, all the raw materials are subjected to backflow for a period of time; S4, a filter is used for filtering the mixture obtained in S3, and then the filtered solution is distilled through a distillation device; S5, the distilled solution in S4 is distilled again to obtain liquid vinyl triisoacryloyloxy silane. The vinyl triisoacryloyloxy silane synthesized through the method is high in synthesis speed, high in efficiency, low in impurity content, high in product purity and good in product quality.