The backlight module is one of the key components of LCD display panels, which functions to provide sufficient brightness and evenly distributed light sources to display images normally. Its luminous effect will directly affect the visual effect of the LCD display module, so the quality of the backlight module is particularly important. The AOI inspection machine for appearance defects of the backlight module can inspect the quality of the backlight module during the process to ensure its quality. The appearance defects of the backlight module include: dirt, scratches, white sides, foreign objects, exposed film materials, film displacement, missing wires, tape climbing, concave frame, high and low backboards of the frame, missing tape, FPC offset, etc; The AOI inspection machine for appearance defects of backlight modules is used to replace manual visual inspection and achieve machine replacement.