An improved combination algorithm is proposed aiming at that the traditional D-S evidence theory is difficult to solve the problem in highly conflict evidence. The concept of closeness is introduced to the D-S evidence combination, and the evidence of consistency value is used to calculate its weight, which achieves a weighted fusion of conflict evidence. The evidence combination method selection standard is proposed, which can be divided into two parts: conflict and nonconflict, and then to fuse the evidence with the improved algorithm and the traditional algorithm respectively. Experiments demonstrate that the proposed method not only has the same functions of information focus as the Dempster rule, but also can solve the problem of the combination of conflict evidence better, and can solve the problems of fault diagnosis in power system and get a quite favorable result.