Sewage primary treatment system

The utility model relates to a sewage primary treatment system. The primary treatment system comprises a first tank body and a second tank body, a suction-filtration tank is arranged between the first tank body and the second tank body, an infiltration tank is arranged in the first tank body, the first tank body and the second tank body are both spaced apart from the suction-filtration tank by waterproof walls with a water-permeable hole, an activated carbon adsorption layer is filled in the bottom of the suction-filtration tank, a coarse sand filler layer is arranged on the activated carbon adsorption layer, and a fine sand filler layer is arranged on the coarse sand filler layer. According to the primary treatment system of sewage, sewage is firstly subjected to primary filtration and adsorption treatment, thereby facilitating the subsequent biochemical treatment.