The invention relates to the field of environmental protection and sewage treatment, in particular to an anaerobic-anoxic-hypoxic integrated reactor. The anaerobic-anoxic-hypoxic integrated reactor is characterized in that: the anaerobic-anoxic-hypoxic integrated reactor comprises an anaerobic zone (3), an anoxic zone (4), a hypoxic aeration zone (5), a degasification zone (6), a sedimentation zone (7), a water inlet pipe (1), a sludge removing pipe (13) and a water outlet pipe (17); the anaerobic zone (3), the anoxic zone (4), the hypoxic aeration zone (5), the degasification zone (6) and the sedimentation zone (7) are sequentially arranged along the direction of water flow and are communicated by underwater holes; the sedimentation zone (7) is provided with the sludge removing pipe (13) and the water outlet pipe (17); as a water distribution tank (2) is provided, the proportion of sewage entering the anaerobic zone (3) and the anoxic zone (4) can be flexibly adjusted; in addition, a movable zone partition plate (20) is provided and can adjust the volume as well as functional location of the anaerobic zone (3) and the anoxic zone (4). The invention can effectively solve the problems of poor effect of synchronously removing nitrogen and phosphorus, insufficient carbon sources, high energy consumption and the like during the running of the traditional A2O reactor.