Using C2H2, CO and n-butanol as raw materials, using PdBr2 as the main catalyst in the synthesis of succinate by the dicarbonylaon under normal pressure and 55℃ conditions. The effects of the amount of catalyst, the type and amount of auxiliaries, the type of solvent, reaction temperature and reaction time on yield of dibutyl succinate, dibutyl maleate and dibutyl fumarate were investigated. The experimental results showed that in optimal conditions : the amount of PdBr2 was 0.04g, n(PdBr2):n(LiBr)=1:8, 0.1mL methanesulfonic acid, the solvent was acetonitrile, n(C2H2):n(CO)=1:2, 101KPa, reaction at 55°C for 3h, the yield of dibutyl succinate, dibutyl maleate and dibutyl fumarate reached 76.11%.