The 5000 tons/day sewage treatment project adopts the UASB treatment process. The two anaerobic units are respectively 2500 ㎥and double film biogas holder is 1300㎥.The anaerobic reactor is mainly used to degrade the organic matter in the sewage, so that the COD value in the sewage after the anaerobic reaction is within the control range. Considering the investment payback period and economic return rate, the generated biogas can be fully utilized. Generally used in combustion boilers to produce steam or hot water. The steam and hot water produced are used for industrial use or daily life. The biogas produced can also be used for power generation. The generated electricity can be used in the factory or daily life. In addition, the heat generated by the boiler or the waste heat generated by the biogas generator is used to heat the anaerobic reactor, thereby solving the disadvantage that the anaerobic reactor cannot maintain the medium temperature anaerobic reaction in cold areas, and correspondingly saves equipment investment.