In the process of line loss algorithm analysis, aiming at the problem that the relationship between line loss and correction data cannot be accurately obtained, an improved line loss algorithm combining line loss correction factor and line loss algorithm is proposed to reduce the influence of abnormal current and voltage on line loss correction results and improve the effect of line loss correction. The line loss of abnormal current and voltage was carried out using the k-means theory, and the irregular line loss judgment strategy was found for each line. Then, under the guidance of the k-means idea, the optimal line loss position is located. The simulation results show that the improved line loss algorithm can improve the accuracy of significant line loss correction under k-means, shorten the line loss judgment time of the entire power grid, and the line loss correction effect is better than that of the line loss method.