Sewage pretreatment device

The utility model belongs to the technical field of sewage and sludge treatment, and particularly relates to a sewage pretreatment device. The device comprises a grit pretreatment tank and a carbon capture tank which are sequentially connected, the grit pretreatment tank comprises a grit tank body, a water inlet I, a grating, a drainage well and an aeration tank, a tank bottom slope and a sand collecting hopper are arranged below the grating, and a water outlet is formed in the lower portion of the drainage well; the carbon capture tank comprises a carbon capture tank main body, a water inlet II and a water outlet tank, a sludge outlet II is formed in the bottom of the carbon capture tank main body, a plurality of biological flocculant adding ports are formed in the side, close to the water inlet II, of the top of the carbon capture tank main body, and partition plates are arranged in the carbon capture tank main body on the sides, close to the water outlet tank, of the biological flocculant adding ports; and