In this paper, a novel CGL structure is designed and studied to improve the lateral leakage in stacked OLED devices. Experiments confirmed that the position of transverse leakage mainly occurred in the CGL layer, and the new CGL structure was realized by optimizing the n‐CGL material. Compared with the reference CGL structure device, the voltage of the new structure device decreased by 0.05v, and the current efficiency increased by 5%. The average value of the color gamuts was improved by 5%, demonstrating the effectiveness and stability of the new CGL structure. The mechanism of the new CGL structure was verified by EOD. The carrier transmission performance of the new CGL structure was worse, but the carrier injection performance was improved, so as to improve the lateral leakage problem under the premise of ensuring the role of CGL.