With the characteristics analysis of city gas pipeline risk as a foundation, there were many uncertainty factors in gas pipeline risk assessment, the existing risk assessment methods affected assessment results due to its own limitations. The model introduce fuzzy analytic hierarchy process, utilizing its strict logic and comparative principle, the risk factor weight of pipeline were resolved in a good solution, effectively reduce the artificial subjective, greater error and lower quantitative in the existing risk assessment methods. This method is showed through the example in city natural-gas pipeline risk assessment serviceability and reliability.