The oxygen concentrator, is energy-saving and safe to use. The optional dual-flow configuration allows two users to inhale oxygen at the same time by sharing one machine. It can be used for adjuvant treatment for respiratory system diseases, cardio vascular and cerebral vascular system diseases, chronic obstructive pulmonary disease, carbon monoxide poisoning and other hypoxia diseases. It is suitable for clinics, community hospitals, township health clinics, etc.