Doublyfed induction generator (DFIG) was widely used in wind power industry. In terms of its structure, the bearing was a very important part of the motor, and its status determined the overall performance of the motor. In the actual wind farm, the motor bearings would be replaced periodically, but this method could not avoid the early fault of the bearing. Therefore, the early diagnosis of the fault was particularly important. First, the bearing fault generation mechanism and failure modes of DFIG were introduced. Then the diagnostic methods frequently used in recent years were classified and described. Finally, based on the existing achievements, the future development trend of DFIG bearing fault diagnosis method was analyzed, so as to make preparations for the possible breakthrough in the field and after the proposal of new methods.