A method of repairing a transistor, for repairing a short-circuit defect of a metal layer between a source and a drain of a thin film transistor; the repairing method including: acquiring a short-circuit region of the metal layer between the source and the drain of the thin film transistor; etching a protective layer located above the short-circuit region with a first wavelength laser; etching the metal layer located in the short-circuit region with a second wavelength laser; and partially etching a channel layer below the short-circuit region with a third wavelength laser.