The invention relates to an energy-saving process for producing melamine, comprising the following steps: using urea as the raw material, and producing melamine, ammonia and carbon dioxide in a reactor under the catalytic function of a catalyst at 350-420 degrees centigrade and a pressure of 0-1.5 MPa through reaction, wherein material gas from the reactor enters a hot-gas cooler, and the cooled hot technological gas enters a filter to be filtered, and the filtered technological gas containing melamine enters a crystallizer, and the melamine after crystallization enters a cyclone separator, and the separated solid triamine is sent to a storage bin to be packaged, and the gas coming out from the cyclone separator enters a heat exchanger; cooling the gas containing ammonia and carbon dioxide at about 200-220 degrees centigrade by water to about 30-145 degrees centigrade, and purifying the technological gas in an urine liquid washing tower; separating urine liquid fog drops carried in the purified gas by a separator, wherein the gas after separation is divided into three ways: one way gas is compressed into the reactor by the compressing machine, and one way gas enters the crystallizer by a cool air fan through pressure boosting to be used as cool air, and one way is a tail gas exhaust system for other purposes. The process disclosed by the invention has characteristics of compact equipment, simple technology, less energy consumption, cost saving and so on.