In order to improve the success rate of repairing AMOLED’s bright pixel defect and optimize the performance of the device, an AMOLED bright pixel defect repairing method is investigated to achieve the sub-pixel cathode isolation. Firstly, a pulsed laser beam with fixed shape and frequency is constructed by a laser repairing device with the laser shaping mechanism (Slit). Then, the laser beam passes through the AMOLED panel encapsulation layer to illuminate the cathode film layer above the target sub-pixel, so that the target sub-pixel luminescent layer is separated from the cathode of the panel. The cathode electrons cannot migrate to the target sub-pixel luminescent layer and the target sub-pixel changes from bright to dark. In this paper, the rectangular repair method and the line repair method are proposed and compared. The results show that the success rate of the rectangular repair method is 33.5%; the success rate of the line repair method is 100%. Compared with the rectangular repair method, the line repair method has a lower reliability risk. Therefore, the line repair method is better. In our study, the repair success rate increases from 96.9% to 100% when the line repair method is introduced into mass production.