Water-in-oil (W/O) emulsions are commonly found in shale oil development processes, and their stability is a key factor in optimizing oil recovery strategies. Specially, as aging occurs, W/O emulsions with different stabilities may break into rag layers, indicating increased emulsion stability and greater difficulty in demulsification. In this study, simulation emulsions similar to the actual emulsion properties in oilfield were prepared using gentle stirring method. Regardless of the stability level, emulsions exhibited a gradual reduction in the height of the rag layers during emulsion aging. Based on droplet size distributions and microstructures, emulsions with high stability show distinct microstructural differences and more pronounced rag layers compared to low stability emulsions. Additionally, high stability emulsions display unique microstructures characterized by the encapsulation of large water droplets by numerous small water droplets. Furthermore, the size, distribution range, and structural morphology of water droplets in high-stability emulsions are less affected by aging time. In contrast, low stability emulsions tend to have larger sizes and lower uniformity of water droplets, leading to the formation of various irregular textures or wrinkle structures during aging. It is proved that aging time has a significant impact on low stability emulsions but has only a minor impact on high stability emulsions. These finds could provide more evidence for the study of the stability and demulsification mechanism of shale oil emulsions, as well as the development of demulsifying agents.