Improved activated sludge process sewage processing system

The embodiment of the utility model discloses an improved activated sludge process sewage processing system, which comprises a biochemical aeration tank, a sedimentation tank and an aeration return-flow system, wherein the aeration return-flow system comprises a sludge tank and an aeration return-flow device; the aeration return-flow device is arranged in the sludge tank; and the aeration return-flow device is provided with a diffusion tube which can be used for simultaneously introducing air and sludge in the sludge tank into the biochemical aeration tank. According to the improved activated sludge process sewage processing system disclosed by the utility model, a traditional sludge process sewage processing system is substantially improved, the sludge return-flow system and the aeration system are combined into a whole, and the project investment and the operation cost are effectively saved on the basis that the aeration efficiency is not lowered; meanwhile, the aeration return-flow system of the processing system adopts a liftable design, the defects that the traditional aeration head needs to stop and clean the tank so as to affect normal operation when being overhauled can be effectively avoided, and the improved activated sludge process sewage processing system is convenient and simple to maintain.