The invention discloses a synthetic method of glycerol carbonate. The synthetic method is characterized in that: N,N-dimethylformamide is mixed with tetraethyl ammonium iodide and glycerol to obtain an electrolyte, the electrolyte is saturated with CO2 at normal pressure and is electrolyzed under conditions of a constant current, and the electrolyte is esterified and distillated to prepare glycerol carbonate. Compared with the prior art, the synthetic method of the invention, which has the advantages of simple technology, convenient operation, safety, cheap and easily available raw material, effective utilization of a greenhouse effect gas carbon dioxide, substantial reduction of atmospheric pollution, realization of the high efficiency conversion of glycerol, and alleviation of the increasingly exhausted energy problem and has a very significant meaning to the environment protection, is a technical route with a good industrial synthetic value.