The present disclosure provides a process for producing dimethyl carbonate with high conversion rate. Alkylene glycol reacts with urea via alcohylysis reaction to produce alkylene carbonate and ammonia. The alkylene carbonate produced reacts with methanol via transesterification reaction to produce dimethyl carbonate. Before the dimethyl carbonate is separated from the mixture, the nitrogen-containing impurities are substantially removed. Unreacted feedstock and catalysts are recycled in the process.