Abstract: This paper proposes a method of energy efficiency evaluation based on the source and load characteristics,and compares the energy efficiency of AC and DC distribution networks. Firstly,a detailed power model of photovoltaics,energy storage,electric vehicles and other office load are developed. Then,based on typical structure of low voltage AC and DC distribution system,the efficiency function of the converter and line loss model are established. The AC and DC energy efficiency comparison method considering power characteristics is studied,and the comparative analysis of energy efficiency based on time sequence is presented under the different operating conditions and capacity proportions in AC and DC systems. Finally,the energy efficiency comparison is presented for the same AC and DC distribution structure based on DC demonstration project.