The invention discloses a preparation method of a high-dielectric performance polyvinylidene fluoride-titanium carbide nano-sheet composite material, relates to a preparation method of a polyvinylidene fluoride composite material and aims at solving the problems of low dielectric constant of the existing polyvinylidene fluoride. The preparation method comprises the following steps of step 1, preparing two-dimensional layered TiC nano-sheets; and step 2, performing compounding to obtain the high-dielectric performance polyvinylidene fluoride-titanium carbide nano-sheet composite material with the mass percentage of titanium carbide nano-sheets being 5-20 percent. The high-dielectric performance polyvinylidene fluoride-titanium carbide nano-sheet composite material prepared by the preparation method can be applied to the field of microelectronic process, integrated circuits and high-efficiency energy storage elements and has the dielectric constant being 9.8-19.1. By adopting the preparation method provided by the invention, the high-dielectric performance polyvinylidene fluoride-titanium carbide nano-sheet composite material can be acquired.