Objective:To evaluate the protection performance of military transport aircraft oxygen system for aircrew and provide the physiological tests basis for product design finalization.Methods:Four dummies and 4 healthy volunteers who were equipped with individual protection equipment and military transport aircraft oxygen system completed 4 tests in altitude chamber including the oxygen supply performance physical test of oxygen system, the rapid decompression physical test of oxygen system, the physiological tests of oxygen continuously supplying for 6 h and oxygen supply performance test in rapid decompression at 12.0 km. Oxygen concentration, respiratory resistance, safety pressure, peak value, peak duration and steady pressure of mask under rapid decompression were tested. Electrocardiograph and oxygen saturation of volunteers were monitored.Results:The oxygen partial pressure provided by military transport aircraft oxygen system under 12.0 km was ≥19.1 kPa corresponding to the respiration ventilation volume of 20 L/min of dummy. The expiratory resistance was no higher than 441.3 Pa and the inspiration resistance was no higher than 490.3 Pa before the safety pressure connected. The peak pressure value in rapid decompression with 1.0 L lung volume of dummy was no higher than 5.8 kPa. The oxygen partial pressure provided by military transport aircraft oxygen system for volunteers was over 21.9 kPa in the 6 h cruising flight. All 4 volunteers successfully completed the rapid decompression physiological tests at 12.0 km with good subjective and objective responses.Conclusions:The protection performance of military transport aircraft oxygen system for aircrew can provide enough protection against the hypoxia up to 12.0 km