Sewage treatment device with low sludge yield and process method

The invention discloses a sewage treatment device with low sludge yield and a process method. The sewage treatment device comprises an anaerobic tank, an anoxic tank, an aeration tank and a secondary sedimentation tank which are sequentially connected along a sewage flowing direction, the sludge pre-reaction tank, the anaerobic sidestream reactor and the pre-aeration tank are sequentially connected along the sludge backflow direction. According to the invention, low yield of sludge in sewage treatment can be ensured; due to the construction of the sludge pre-reaction tank, the construction cost and the occupied area of the anaerobic flow measurement reactor can be reduced by about 50%, and meanwhile, the anaerobic stability is ensured; the pre-aeration tank is newly added, anaerobic sludge is subjected to self-flocculation to prevent blockage, the phosphorus removal effect can be indirectly improved by 5-8%, and the competitive advantage of the slowly growing microorganisms is improved. The built aeration-pre