It is verified that an organic light-emitting display (OLED) device combined with an advanced optical film characterized by the optical combination of a pyramid-shaped structure coupled with light absorber simultaneously satisfies highly enhanced light extraction and lowly ambient light reflection as one of the long-awaited needs of OLED. Thus, it does not require a polarizer that reduces optical efficiency in the OLED device. The results of the optical calculation for the OLED device combined with the proposed film indicate that its optical efficiency has been remarkably improved in the entire visible light region, compared to the polarizer-based OLED device. Then, its external light reflection is approximate to 10%, which shows it is lower than when a polarizer and optical films are used to reduce the reflection of ambient light. The experimental data of the OLED device coupled with a film for enhancing optical efficiency (FEOE) confirms the intriguing results of the simulation and thus corroborates the fact that FEOE improves the optical efficiency of OLED devices. The highly efficient FEOE-based OLED will be of significant interest in materials science and display devices.