The invention discloses a method for synthesizing 1,2,3,4-tetrachloro-1,4-dialkoxy-1,3-butadiene. The method comprises the following steps: reacting an alkali compound with hexachlorobutadiene in an alcoholic solution, wherein the molar ratio of the alkali compound to hexachlorobutadiene is (2.5-5.5):1, the molar volume ratio of the alkali compound to the alcoholic solution is (4-6.5):1mol/L, the reaction temperature is 60-150 DEG C, and the reaction time is 2.0-10.0 hours; cooling after the reaction is ended, performing reduced pressure distillation, and performing suction filtration and rectification to obtain the product 1,2,3,4-tetrachloro-1,4-dialkoxy-1,3-butadiene. The method has the advantages of simple process, high yield and low cost.