NOVELTY - Upflow anaerobic sludge bed reactor comprises reactor, sludge bed, sludge suspending layer zone, gas collecting hoods, connecting tubes, sludge risers, gas collecting tank, gas outlet tube, sludge return tube, water outlet channel, and gas chamber. The lower end of reactor is connected to the sludge bed; and the upper end of reactor is connected to the sludge suspending layer zone. The upper end of the reactor is connected with multiple gas collecting hoods that are connected with one another through connecting tubes. The gas collecting hoods are connected to the gas collecting tank.    USE - Upflow anaerobic sludge bed reactor.    ADVANTAGE - Compared with prior art traditional reactor, which can only return the sludge to the upper part of the reaction zone of the reactor, the upflow anaerobic sludge bed reactor can carry the biogas out of the sludge and return the sludge to the bottom of the reactor through sludge return tube, where sludge that is returned back to the bottom of the reactor can be sufficiently mixed with water to improve treatment effect of wastewater.    DETAILED DESCRIPTION - Upflow anaerobic sludge bed reactor comprises reactor, sludge bed, sludge suspending layer zone, gas collecting hoods, connecting tubes, sludge risers, gas collecting tank, gas outlet tube, sludge return tube, water outlet channel, and gas chamber. The lower end of reactor is connected to the sludge bed; and the upper end of reactor is connected to the sludge suspending layer zone. The upper end of the reactor is connected with multiple gas collecting hoods that are connected with one another through connecting tubes. The gas collecting hoods are connected to the gas collecting tank through multiple sludge risers. The upper and lower ends of the gas collecting tank are respectively connected to the gas outlet tube and the sludge return tube. The water outlet channel and gas chamber are respectively arranged between each of the both sides of the gas collecting hoods and the reactor.