The sewage contains the blood from carcass, the water used to clean the carcass and some sanitary sewage. The total discharge is 360 ton per day.After the analysis, the ingredient of the sewage is very complex and in high concerntration, which also contains many viruses like Echerichia coli. Therefore we must treat the sewage in order to prevent the containation. At the same time, the sewage system cut the water consumption by water recycling. The treated sewage should reach the national No.1 class effluent standard. The investment and working cost should be reduced as mush as possible. The design should be practical, and the miantenance should be easy and convenient.