The invention discloses a display panel maintaining method, device, equipment and system, and belongs to technical field of displays. The method comprises the following steps: controlling a laser transmitter to emit laser to different positions of a filter unit at N different laser polarization angles, so that the filter unit is carbonized, and a first carbonized filter unit is obtained, wherein the first carbonized filter unit comprises N first carbonized points in one-to-one correspondence with the N different laser polarization angles; determining a first target carbonized point meeting a first preset condition from the N first carbonized points; determining a target polarization angle corresponding to the first target carbonized point; controlling the laser transmitter to emit laser to the first carbonized filter unit at the target polarization angle, so as to maintain a sub-pixel to be maintained. According to the display panel maintaining method, device, equipment and system, the problem of relatively poor maintaining effect in the prior art is solved; the maintaining effect is improved. The display panel maintaining method, device, equipment and system are used for maintaining display panels.