The invention provides a new method for separating azeotropic mixture of methanol and methyl carbonate. The invention is characterized in that the mixed solution of methanol and methyl carbonate is supplied in circulation at the upstream side of molecular sieve membrane, and the downstream side of the molecular sieve membrane is connected to a vacuum system. As the molecular sieve membrane has the very high permselectivity for methanol, methanol in mixed solution preferentially permeates through the molecular sieve membrane, and vaporization and desorption are carried out at the downstream side of membrane, and then methanol is condensed and collected by the vacuum system. After multiple circulations, the mixed solution can achieve the complete separation of methanol and methyl carbonate. Compared with the traditional rectification method, the method of the invention has advantages of low energy consumption, no pollution, compact device, high separation efficiency, and the like, and has a very important meaning for industrial production of methyl carbonate and the preparation of other organic chemical materials by using methyl carbonate.