The development of civil aircraft requires the collaboration and support of suppliers, so the choice of civil aircraft supplier is crucial. In order to meet the design concept of modern civil aircraft that emphasizes reliability, maintainability and testability, the article proposes a method for selecting civil aircraft suppliers based on the three indicators.. Firstly, the classification of civil aircraft suppliers is introduced. Secondly, the selection criteria considering different types of civil aircraft suppliers are established, and the subordinate indicators corresponding to each criteria are listed. Finally, the Analytic Hierarchy Process method is selected to establish the selection model of the oxygen system suppliers as well as make expert score simulation, and the importance of the indicators and criteria of different suppliers were obtained. On this basis, the supplier with better performance is selected,thus providing a reference for the selection of civil aircraft suppliers considering reliability,maintenance and testability indicators.