The invention provides a synthetic method of 5,5,5-trichloro-2-methyl-2-pentene. The synthetic method comprises the following steps: taking 2-methyl-3-butene-2-ol as an initial compound of a reaction;adding a haloid acid into the reaction system, and conducting distilling to obtain an intermediate product 1-halo-3-methyl-2-butene; adding the intermediate product and chloroform into a reaction kettle, conducting stirring at a low temperature, and adding an inorganic base into the system in batches; wherein the reaction temperature is 0-40 DEG C, the reaction time is 2-10 hours, the mass ratioof the 2-methyl-3-butene-2-ol to the haloid acid in the reaction is (0.3-1):1, the weight ratio of the chloroform to the 1-halo-3-methyl-2-butene is (1-10):1, and the weight ratio of the inorganic base to the 1-halo-3-methyl-2-butene is (0.1-2.0):1. The method is high in reaction yield and low in environmental pollution degree, and the corrosion degree of equipment is reduced.