The present disclosure discloses a method and system of determining a location of a line fault of a panel. The method comprises: connecting a front end point of a metal wire that is determined to have suffered the line fault to a probe of a test instrument, the other probe of the test instrument being connected to a common electrode wire; performing a fusing-off processing on the metal wire according to a preset rule; and determining the location of the line fault of the metal wire based on a variation in the readings from the test instrument upon the fusing-off of the metal wire. The system comprises: a test instrument, one probe of which being connected to a front end point of a metal wire that is determined to have suffered the line fault, the other probe of which being connected to a common electrode wire; and a laser for performing a fusing-off processing on the metal wire. The short circuit of the metal wire may be localized at a pixel cell level using the method and system according to the embodiments of the present disclosure.