Abstract: Color oil filling and coupling are critical parts of electrofluidic display fabrication process. How to improve the uniformity and efficiency of the filling process is still a critical challenge for electrofluidic displays technology. A novel oil filling and coupling approach based on phase manipulation is proposed in this paper, which allows the filling conducting in the atmospheric environment, while carrying out the coupling in the liquid environment with the oil in frozen condition. The complexity caused by oil/water/solid interface manipulation in traditional filling method is avoided in this proposed approach, which improves the stability and compatibility of the filling process. The oil thickness analysis indicates the phased manipulation filling method giving a better controllability compared to traditional self-assembly method. The electro-optical response performance of the display device using phase manipulating method is comparable with that using normal process. This work provides a powerful method for overcoming the filling and coupling bottleneck in electrofluidic display manufacturing, and will accelerate the commercialization of electrofluidic display technology.