This study investigates the microscopic properties of water?in?oil (W/O) emulsions, focusing on their stability and the formation patterns of liquid holdup. Through emulsification experiments and microscopic observation, the effects of water content, shear rate, and carbon dioxide (CO₂) treatment on emulsion droplet size distribution and stability were systematically studied. Based on experimental data, a liquid holdup rate model was developed for the MH oil sample. The results indicate that the shear rate significantly affects the droplet size distribution and emulsion stability. A moderate shear rate (6 000~9 600 s^-1) promotes emulsion stability and yields a uniform droplet distribution. When water content is below 30%, increasing the water content reduces the droplet size; however, high water content can show phase separation. CO₂ saturation treatment can reduce interfacial tension and improve emulsion stability, but excessive CO₂ release may destabilize the oil?water interface and promote droplet coalescence. Rational control of shear rate, water content, and CO₂ concentration can effectively optimize pipeline transportation performance, reduce bottom liquid accumulation, and enhance the operational stability of the oilfield gathering and transportation system. This study provides theoretical support for the control of liquid holdup in CO₂?driven gathering pipelines and holds significant engineering application value for oilfield production management.