It can be difficult to locate the fault section of a distribution network. To help tackle this, a new fault location method based on the magnetic field difference between behind and ahead of fault point is proposed. First, the distribution of the x-axis and y-axis magnetic field at the tower and its relationship with phase current are analyzed. At the same time, the influence of the arrangement difference of three-phase conductors and the length of data window on the magnetic field is considered. Secondly, based on the magnetic field difference between the x-axis and y-axis upstream and downstream of the fault point, the similarity analysis of the biaxial magnetic field is carried out from different angles, and five new positioning criteria are constructed. Finally, the five location criteria are fused by D-S evidence theory, and the section with the greatest probability is determined as the fault section. Because of the advantages of each criterion, this method overcomes the adaptability problem of a single criterion. The effectiveness of this method is verified by a simulation test of a high impedance fault, noise interference and other working conditions. This work is supported by the National Natural Science Foundation of China (No. 52177114 and No. 61403127).