Collector lines in wind farms mostly contain multiple branches,and generally only one measuring device is set at the head of the line. If single-end fault locating is carried out based on the device after a fault,only multiple suspected fault points can be obtained on different branches,and the actual fault branch cannot be determined. Although the current multi-terminal algorithm can locate the fault branch,the number of measuring devices required is too much,which is expensive. In this paper,the topological structure of a collector line is analyzed under the most common single-phase grounding fault. It is pointed out that when faults occur on different branches,the same data may be collected by the single-end measuring device,making the fault branch cannot be identified only by the single-end electrical volume,so it is necessary to add measuring devices to identify the fault branch. In order to reduce the investment,the minimum number and location of additional measuring devices required to identify the fault branch on lines with different topologies are determined. Combined with the new measurement information and the existing single-terminal method,an algorithm is proposed to locate the fault branch and achieve fault location based on multi-terminal fault recording information. The effectiveness and practicability of the proposed method are verified by PSCAD/EMTDC simulation. The proposed algorithm is improved from the single-terminal impedance method to solve the problem of fault branch location,and it can be realized by adding a few measuring devices on the basis of the current configuration. The cost is low,which means a good engineering application prospect.