Aiming at the calculation requirements of the theoretical line loss level of the station line loss lean management, amethod for estimating the line loss of the theoretical line loss based on the correlation degree variable weight is proposed. Firstly, theinfluencing factors of theoretical line loss are analyzed and a theoretical line loss evaluation index system including the inherentcharacteristics of the station area and operational factors are established. Then, Spearman coefficient, grey correlation degree and cosine quantitative analysis method are used to construct the evaluation index. The evaluation method of the theoretical line loss of thestation area is proposed. Finally, the theoretical line loss level is analyzed by using six different types of stations in Anhui as an example to verify the effectiveness of the proposed method.