The invention discloses a partial discharge positioning method based on mode identification. The method includes the steps of (1) acquiring a plurality of partial discharge signals with known discharge source positions and correspondingly extracting a plurality of first signal characteristics; (2) establishing a partial discharge characteristic information database including a plurality of first signal characteristics and corresponding discharge source positions; (3) acquiring the partial discharge signals with the discharge source positions to be determined and correspondingly extracting second signal characteristics; and (4) based on the partial discharge characteristic information database, matching the second signal characteristics and the first signal characteristics based on the mode identification to find the first signal characteristics closest to the second signal characteristics, and taking the discharge source positions corresponding to the first signal characteristics as the discharge source positions of the second signal characteristics. In addition, the invention further discloses a corresponding system. The method and system can accurately position the discharge source positions of the partial discharge, and are easy to realize.