Abstract: Based on the seismic profile identification of a mud volcano in the Shenhu area of the northern South China Sea, this study used coupled Eulerian-Lagrangian (CEL) algorithm to simulate the motion process of the material inside the mud volcano. Through the comparative analysis of different stages, this study indicated the formation mechanism of mud volcano and summarized the motion characteristics and rules of the materials in the mud volcano. The numerical modeling results showed that the fluid migration styles during the formation of mud volcano took place obvious changes in different stages, showing the irregular change law of fluid stress and strain during the fluid migration. Then this study analyzed the intensity variation trend of stress, strain and energy during the formation of mud volcano. In the process of fluid penetrating upward, the force distribution of the stratum shows obvious unevenness, and the protrusion in the middle part breaks and causes the uplift of the strata on both sides. The characteristics of the internal fluid during the formation of mud volcanoes provided by the simulation results in this study can promote the further understanding of the formation mechanism and process of mud volcanoes, and provide a theoretical guidance for the deep diapiric structure and hydrocarbon migration.