The invention discloses an automatic off-line gas-water combined-washing membrane bioreactor, comprising a PLC automation control cabinet, a MBR reactor, a MBR membrane assembly, a rotating hood, an annular guide rail, a lifting device, a washing pipe network, an external interface, a gas washing pipe, a water washing pipe, a gas pump and a water pump, wherein the gas pump, the water pump and the three-way change valve are all connected with the PLC automation control cabinet, the washing pipe network is provided with several nozzles. The present invention adopts a full PLC automation control system, the PLC automation control cabinet controls a pressure washing pump (gas pump and water pump), and gas or water is injected into the washing pipe network by flexibly adjusting the three-way change valve, so that the operation is simple, the cleaning is complete, and the manual operation load is reduced.
