The invention relates to a method for reducing the separation energy consumption of a product in the process of preparing ethylene glycol by hydrogenation of dimethyl oxalate. The method comprises thefollowing steps: (1) performing one-stage condensation on a product liquid obtained by a reaction of preparing the ethylene glycol by hydrogenation of the dimethyl oxalate, and performing separation,wherein a condensed gas phase continues to perform two-stage condensation, and a condensed liquid phase enters into a No.2 methanol removing tower for rectification separation, so as to obtain methanol; and (2) after two-stage condensation separation is performed, and enabling a liquid phase to enter a No.1 methanol removing tower, so as to obtain methanol at the top of the tower through separation and obtain a one-time rectification tower kettle liquid at the bottom of the tower, wherein the one-time rectification tower kettle liquid enters the No.2 methanol removing tower, and continuing rectification separation to obtain methanol. Compared with the prior art, the method provided by the invention performs two stages of condensation on the hydrogenation product liquid, and separates themethanol by using two towers, so that the method can sufficiently reduce the usage amount of condensation cooling capacity, and at the same time, the energy consumption of the rectification towers canbe reduced through adjustment of the reflux ratio and the output amount in the two towers.