The technology of CO2 enhanced oil recovery (EOR) has rapidly developed due to its significant advantages in oil recovery enhancement and carbon sequestration. The formation of a CO2-oil miscible phase can notably improve the efficiency of CO2 flooding. However, in most of China's oil fields, the minimum miscibility pressure (MMP) for CO2 miscible flooding exceeds the formation fracturing pressure, making CO2 miscible flooding impractical. Therefore, reducing the MMP has become a primary focus and challenge in current research on CO2 EOR technology to enhance oil recovery. This paper summarizes four categories of methods to reduce the MMP by investigating the research results of CO2 flooding technology both domestically and internationally. These methods include reducing reservoir temperature, using supercritical CO2 microemulsions, miscible solvents, and surfactants. The first three categories of methods are not scalable due to poor economic benefits and environmental concerns. Among surfactants, three types are primarily considered: fluorocarbon, hydrocarbon, and siloxane. Hydrocarbon surfactants offer better application value due to their higher activity, lower pollution, and lower cost. The key is to find a suitable CO2-philic structure. Cost is the primary factor affecting the development of surfactants. Developing amphiphilic surfactants with excellent performance, low cost, and environmental friendliness is a hotspot direction for reducing the MMP of CO2 flooding in the future.