Abstract: Referencing the basic theory and technology of pipeline risk assessment and disposing method in foreign countries and combined with real working conditions in combined-stations in China, a risk assessment system for combined-stations tallying with China's situation by using fuzzy poly-assessment method of fuzzy mathematics is set up and a model of fuzzy mathematics to assess the risk of combined-stations is raised based on risk assessment index system. And a complete system of fuzzy failure factors and fuzzy consequence factors for combined-stations is established, which constitutes an objective criterion to assess the failure and consequence factors of combined-stations.