Abstract: The current method of locating the grounding fault of distribution networks fails to consider the characteristics of the complex distribution network, which leads to low accuracy,long positioning time and large error from the actual fault distance. Therefore,this paper proposes a grounding fault location method for the complex distribution network based on impedance analysis. Based on the analysis of the impedance characteristics of the complex distribution network, the relationship between the actuation point impedance and load impedance characteristics of distribution network transmission line is obtained,and it is extended to different connection impedances of distribution network transmission line. The distribution network is transformed into an abstract diagram,and the end deformer is installed into the distribution network in the diagram. The distribution network is transformed into an abstract diagram. When the end transformer is installed at the top of the distribution network in the diagram,once the distribution network fails,the fault traveling wave will spread to the end of the distribution network along the line of the distribution network. At this time,the traveling wave fault location is carried out to complete the grounding fault location of the complex distribution network. The experimental results show that the proposed method is more accurate and effective in the grounding fault location of the complex distribution network through the fault location accuracy test of different branches,test of the distance from the actual fault and the fault location time test.