The invention provides a calculation method for statistic line losses. The method comprises the step of judging whether position-switched electric energy meters exist in all electric energy meters of user sides connected to a distributing line to be measured in a current acquisition cycle, the step of calculating statistic line loss contributions made by the position-switched electric energy meters to the distributing line to be measured in the current acquisition cycle, and the step of subtracting the statistic line loss contributions made by the position-switched electric energy meters to the distributing line to be measured in the current acquisition cycle and electric energy differences of non-position-switched electric energy meters in the current acquisition cycle from an electric energy difference of a total electric energy meter in the current acquisition cycle, dividing the final difference value by the electric energy difference of the total electric energy meter in the current acquisition cycle, and determining the obtained calculation result as the statistic line losses of the distributing line to be measured in the current acquisition cycle. Influences, caused by position switching of the electric energy meters among different distributing lines, on statistic line loss calculation are fully considered, the accuracy rate of the calculation result is high, the line loss management level is improved easily, and a reliable data support is provided for economical operation of a power system.