The invention provides a sludge circulation type continuous loop-type reaction tank (4), which is divided into a first reaction tank (4a) connected with a sewage and wastewater supply pipe (2) and a second reaction tank (4b) connected with a treated water discharge pipe (10). The inner bottom of the first reaction tank (4a) and the second reaction tank (4b) is equipped with an air disperser (8b) and the air disperser (8b) is connected with a bellows (8) via an air supply pipe (8a). The lower end of the first reaction tank (4a) extends to form a sludge recovery pipe (18). According to the invention, the processing load of sewage and wastewater is dispersed into two reaction tanks so as to improve processing efficiency. Meanwhile, a decanter is not provided, so that the waste water treatment is more reasonable and economical.