Aiming at the problem of low accuracy of topological identification of substation area based on electrical distance clustering, a line-phase-house topology identification method based on the characteristics of wire impedance is proposed to improve the robustness of clustering. Firstly, the voltage time variation characteristics of the head-end electricity meter in the substation area are analyzed in mechanism. Using correlation clustering will have the problem of phase line clustering errors. On this basis, an improved model of topology identification method based on constant analysis of wire impedance is proposed. The method derives the wire impedance between the down-consumer point and the meter by calculating the down-consumer point voltage, checks and corrects the voltage clustering results according to the evaluation index of impedance constancy. Then, a topology identification model for current optimization is established for the corrected clustered meters. Finally, the feasibility and effectiveness of the proposed method are verified by the analysis of the simulation substation area and the actual substation area.