At present, wellmaster and oreda database of well barrier component failure probability is widely used in quantitative risk. However, the data in this database are from offshore oil and gas wells abroad, so the accuracy and applicability of the database are poor for high-temperature and high-pressure sour gas wells in Sichuan Basin. Therefore, according to the characteristics of high temperature, high pressure and high sulfur gas wells in Sichuan Basin, combined with the analysis of the quality, service environment, test results and management level of barrier components of each well, this paper studies the calculation method of failure probability under the actual service conditions of well barrier components. The evaluation indexes are divided into target layer, criterion layer and scheme layer by using the analytic hierarchy process. The evaluation matrix is established by using the 1-9 scale method to add the failure influencing factors Weight weight calculation can realize the combination of qualitative and quantitative methods, and accurately obtain the failure probability values under different well conditions and well barrier status. The analysis shows that the failure probability correction calculation method based on AHP can effectively combine the known data of the influence degree of each component to correct the failure data of the database more accurately.