Abstract: The channeling plugging system using wet-phase controllable expanded graphite (WCEG) had demonstrated broad application prospects in the control of steam channeling during steam injection in heavy oil due to its unique advantages, including the durability of inorganic materials, inherent flexibility and self-lubrication over extended distances, and effective control in complex media via high-temperature expansion. To further clarify the factors influencing the regulation of steam channeling pathways, as well as the channeling & plugging characteristics and distribution behavior of WCEG in porous media, the effects of expansion temperature, particle size, permeability, steam dryness, and crude oil viscosity on the plugging effect of WCEG have been studied through single-core displacement experiments and the CRITIC (Criteria Importance Through Intercriteria Correlation) CRITIC objective weighting method. The results indicate that the plugging effect of WCEG is positively correlated with expansion temperature. When the steam temperature reaches 300 °C, the plugging rate reaches 89.42%, and oil recovery increases by 18.6 percentage points. For particle sizes of 20 to 50 μm, the plugging rate exceeds 75%. The plugging effect deteriorates with increasing permeability; in low-permeability media, the plugging rate reaches 91.23%, and oil recovery is increased by 19.8 percentage points. At a steam dryness of 98%, resulting in an incremental oil recovery of 13.6 percentage points. At 250 °C, crude oil viscosity has a minimal influence on the plugging effect. According to the CRITIC objective weighting method, the main factors influencing the plugging effect in descending order are permeability, expansion temperature, injected particle size, steam dryness, and crude oil viscosity. This study provides a theoretical basis and technical support for the application of WCEG in steam channeling pathway regulation in heavy oil reservoirs.