A jet anaerobic bioreactor for treating a high-concentration organic sewage, comprising a reactor main body zone (1), and a gas purification zone (2) and a separation sedimentation zone (3) provided on two sides thereof. The reactor main body zone (1) is connected to an outlet end of an ejector (5) via an injection pipe (4), the water inlet end of the ejector (5) is connected to the separation sedimentation zone (3) via a circulating water pipe (6), and the gas inlet end of the ejector (5) is connected to the gas purification zone (2) via a biogas pipe (7). A mixed liquid connection hole (8) in communication with the separation sedimentation zone (3) is provided in the middle part of the reactor main body zone (1), and a sludge return hole (9) in communication with the bottom of the reactor main body zone (1) is provided at the bottom of the separation sedimentation zone (3). The reactor realizes complete and uniform mixing of the sewage and sludge and fluidization in the reactor by means of a biogas anaerobi
