The invention discloses a method for reducing a reject ratio of a level black-white line of a liquid crystal panel, relating to the technical field of production of the liquid crystal panel. According to the method, ageing treatment is conducted on the liquid crystal panel after a detecting or cutting process. The method provided by the invention not only can reduce the reject ratio of the level black-white line and improve product quality, but also is convenient to implement; and the process control is easy to carry out. Furthermore, the method further can sufficiently use equipment limited at present, so that the process cost is reduced, and the configuration optimization is realized.