The cabin of the civil aircraft needs to have ventilation function to ensure the health and safety of the passengers on board, and this function is achieved through the air conditioning system. The design and manufacture of air conditioning systems for civil aircraft must comply with the provisions of the airworthiness standards adopted by the relevant models. This paper introduces the airworthiness requirements of ventilation in Article 831(a) of Part CCAR-25 applicable to large civil aircraft, analyzes the compliance of civil aircraft air conditioning system with ventilation airworthiness provisions through flight test methods under normal and possible failure conditions, and designs normal ventilation flight test and emergency ventilation flight test. The calculation method of fresh air per capita in cockpit and cabin is given, and the flight test of emergency ventilation for a certain type of civil aircraft is carried out. The test data are compared with the requirements of the provisions. The results show that the design method of emergency ventilation flight test for civil aircraft is feasible and reliable.