Abstract: A combined aerobic and anaerobic treating method and facility for treating hog wastewater, in which, wastewater flows through six consecutive steps, namely: 1 raw wastewater tank 2 grit removal chamber 3 natural solid-liquid separation device 4 equalization basin 5 aeration tank and 6 final clarifier, and is effectively treated by way of microbiological technology, without adding any chemical precipitatant or coagulant, from highly polluted hog wastewater to qualified effluent for normal discharge. Not only can it help reduce river pollution, but also will be free from secondary pollution by adding chemical additives. An organic fertilizer, which can be directly utilized is a by product.