Abstract: According to a refined oil pipeline rerouting project, identified the high consequence area (HCAs) of the pipeline rerouting project and determined the risk level of HCAs. The evaluation index system of failure probability of oil pipeline was established by selecting five first level indexes:corrosion, third-party damage, misoperation, ontology factor and management. Three segments of the pipeline were divided, and the weight of each index was calculated by game theory weighting method to determine the failure probability of the pipeline. With the help of CFD software, the rule of oil vapor diffusion after pipeline leakage was analyzed. The results show that the HCAs grade of the pipeline rerouting project was in grade II as a whole, and the pipeline segment 2 was more likely to fail. The main causes of pipeline failure were the third-party damage and corrosion. With the increase of wind speed, the diffusion range of oil vapor increase, but the content decrease. The assessment results were in accordance with the actual situation, which provided a certain basis for the application of risk assessment of pipeline rerouting project.