The invention relates to a staged membrane bioreactor device, for treating sewage or micro-polluted source water, with a water container, pertaining to the environmental protection technology field. The device consists of a half-reaction zone, an anaerobic reaction zone, an aeration reaction zone and a pure water zone. The half-reaction is communicated with the bottom of the aeration zone, the bottom of the half-reaction is provided with an empty valve, one side of the half-reaction zone has a water inlet pump, the inside of the half-reaction has an internal ring filled with stuff, and the top of the half-reaction is provided with a stirrer, and the effluent of the half-reaction automatically flows into the anaerobic reaction zone. The top of the anaerobic reaction zone is provided with a stirrer, the bottom thereof is provided with a sludge empty valve, and a sludge empty device is shaped like a horn mouth and positioned in the anaerobic reaction zone, and the top of the anaerobic reaction zone is provided with a drug feeding mouth. The bottom of the aeration reaction zone has an internal return pump, the lower part of the aeration reaction zone is provided with an aeration pipe with an air inlet positioned at one side of the aeration reaction zone, and a fan is connected to the aeration pipe through the air inlet; the top of the aeration reaction zone is provided with an overflow pipe, the bottom of the aeration reaction zone is provided with an empty valve, while the middle is provided with a membrane component. The pure water zone is divided into two units, and the inside of each unit is provided with an effluent valve. The invention has the advantages of good effluent quality, multi purposes, small land occupancy, flexible and convenient using method, and is applied to the treatment of domestic sewage and micro-polluted source water, and can widen and facilitate the application of membrane bioreactor water treatment and water resource reutilization technique.