Statistical line loss is widely used in line loss management, but relevant research on accuracy of statistical line losses is scarce. Therefore, this paper analyzes the error factors of statistical line losses accuracy, including measurement device error and difference of device configuration, and puts forward synthesis method of gateway energy measurement error on the basis of analyzing metering error on the actual operating conditions. Besides, energy upload protocol would have a great influence on statistical line loss when the time interval is small. Combined parameters of the line with the actual load verification data of metering device, it is verified that the existing gateway metering devices configuration scheme would have a great impact on the accuracy of statistical line loss under the actual operating conditions by simulation. This work is supported by National Key Research and Development Program of China (No. 2016YFA0401703).