In this Work, Colorfilter on encapsulation (COE) technology, as a new display technology, is accelerating its application to various OLED display device terminals; however, due to the prepositioning of the depolarizer technology to the screen manufacturing process (usually after the TSP), the COE Panel is often affected by the front‐end manufacturing process and has certain edge‐brightening issues. In this study, we explore the edge‐ brightening or edge‐coloring issues of COE products based on the main influencing factor of the Ink Jet Printing (IJP) film edge morphology, and solve the related problems through process optimization. We also develop process rules.