The provision of oxygen is an important function of commercial aircraft, which is defined as providing the necessary oxygen for the safety of everyone on board, including crew oxygen, passenger oxygen, and portable oxygen. This article adopts SysML modelling language and proposes a model-based architecture modelling method for providing oxygen function for commercial aircraft. It transforms traditional experience and document-based system engineering work into functional architecture system engineering work, and utilises the correlation and traceability relationships of models to achieve state machine modelling for providing oxygen functional architecture. Through simulation verification, the functional architecture modelling method that provides oxygen can be effectively applied to the architecture of other systems.