Abstract: Based on fault tree of oil and gas pipelines leakage, fallibility model for leakage accidents of oil and gas pipelines and its influence factors is established, which realizes quantitative evaluation for oil and gas pipelines, Fuzzy numbers which represent expert opinions are translated into fuzzy possibility scores by using left and right fuzzy preference relation method, and expert weights are considered to amend the formula.Through setting up different fuzzy analytic hierarchy process model and using fuzzy complementary judgment matrix, weights of experts and basic cases are determined.In addition, compatibility and consistency of fuzzy complementary judgment matrix are tested respectively to ensure reliability of expert decision-making.Failure probabilities of incidents can quantitatively reflect influence degree of the incidents to reliability of pipelines, Calculation cases are analyzed according to the model.