The preparation method of Ethyl 2,3-dicyanopropionate is to add potassium cyanide solution and ethyl cyanoacetate into the reaction flask, use dimethyl sulfoxide as solvent, slowly add formaldehyde solution to the solution, and maintain the reaction temperature at 5 ℃ After the addition, the reaction was continued at 20°C for 15h, then the reaction solution was added to ice water, the organic layer was separated, the aqueous layer was extracted with a solvent, the organic layers were mixed, dried and desolubilized to obtain the product. Reaction equation:
HCHO+KCN+CNCH2COOC2H5→CNCH2—CHCNCOOC2H5
