Active sludge circulating device with internal circulation

The utility model relates to the technical field of sewage treatment, and provides an active sludge circulating device with internal circulation, which comprises an inner box body, an outer box body, an upper box body and a lower box body, the outer box body is sleeved on the outer side of the inner box body, a settling zone is formed between the top of the lower box body and the outer box body, and a channel communicated with the inner box body and the settling zone is formed at the bottom of the upper box body and the top of the lower box body; a slurry channel is formed between the side wall of the lower end of the lower box body and the side wall of the outer box body, the side wall of the lower end of the lower box body is of a net structure, the slurry channel is communicated with the settling zone, a jet aerator is arranged in the lower box body, and a slurry discharge pipe is arranged between the side wall of the bottom of the lower box body and the outer box body; the sludge circulating device is use