Voltage loss is a common condition of the metering failure of the electric energy meter. Under the condition of voltage loss, the energy meter can not work properly, resulting in the overall measurement loss and less power. There are two methods for calculating the make?up electric power, namely the power ratio and current ratio calculation method, but due to the large error of the estimation results, the work cannot be carried out smoothly. A new method for the make?up electricity is proposed, which can realize more accurate power calculation results by reading the internal data of the electricity meter.The experimental results show that the proposed method can achieve the accuracy of nearly 100% in the case of three?phase voltage balance.In addition, the method proposed can also be applied to the electric quantity settlement of the power meter screen.At present, this method has been successfully applied to the metrology related work of State Grid Tianjin Chengxi Power Supply Company.