Abstract: Oil pipelines in mountainous regions are vulnerable to natural disasters, third-party construction, and other risk factors due to the complex geological environment. To understand the diffusion patterns of oil pipeline leakage and the impact of terrain on leakage paths, a scientifically-grounded oil spill containment and control scheme was developed to support leakage prevention and emergency response. Utilizing the digital elevation model(DEM)and computational fluid dynamics(CFD)technology, along with real terrain data, the numerical simulation of oil pipeline leakage in complex mountainous terrain was conducted. The diffusion paths of leaked oil were simulated under varying internal pressure conditions to qualitatively analyze the effects of topographic relief and surface characteristics on the diffusion pattern. Additionally, the nonlinear relationship between leakage area and pipeline internal pressure was quantitatively examined. The findings indicated that the diffusion path of leaked oil is significantly affected by the elevation differences and surface features of mountainous terrain, with an observed nonlinear growth trend in diffusion range as internal pressure increases. A leakage containment and control scheme for oil pipelines in mountainous regions was proposed, incorporating numerical simulation to enhance leakage prevention and control capabilities.