When the COB LED display screen is black, the ink color difference between COB LED modules may appear. In order to ensure the consistency of ink color on the same side of COB LED display, this paper studies the ink color collection, classification and sorting algorithm of COB LED display module. Firstly, the ink color acquisition method based on machine vision COB LED display module is introduced, and then, the ink color acquisition device aiming at the optimal effect of viewing COB LED display screen ink color by vision is developed. The COB LED display is completed by using the ink color classification and sorting algorithm based on machine vision. Finally, through the engineering case experiment, the feasibility of COB LED display module ink color collection, classification and sorting scheme based on machine vision is verified, which meets the consistent feeling of human vision as observing a COB LED display.