The invention relates to a preparation method of 2, 3-dialkyl succinic acid and ester compounds thereof. 1, 2-dialkyl-1, 1, 2, 2-tetra (alkoxy carbonyl)ethane is prepared through the dimerization coupling reaction of 2-alkyl-malonic ester compounds, then the 2, 3-dialkyl succinic acid is prepared by carrying out hydrolysis and decarboxylation reaction, and the 2, 3-dialkyl succinate compounds areprepared by further esterification. The preparation method is conductive to the commercial production of the 2, 3-dialkyl succinate and can be used for preparing a Ziegler-Natta polypropylene catalyst as an internal electron donor compound. The preparation method can be used in the technical field of petrochemical polypropylene.