Papermaking wastewater mainly comes from two production processes of pulping and papermaking in papermaking industry. Pulping is to separate the fibers from the plant raw materials, make them into pulp, and then bleach them; paper making is to dilute, shape, press and dry the pulp to make paper. Both processes discharge large amounts of waste water. The waste water from pulping is the most serious pollution. The effluent from the pulp washing is black brown, which is called black water. The concentration of pollutants in the black water is very high, the BOD is as high as 5-40g / L, containing a large number of fibers, inorganic salts and pigments. The waste water from bleaching process also contains a lot of acid and alkali substances. The waste water discharged from the paper machine is called white water, which contains a large number of fibers and fillers and rubber materials added in the production process. The treatment of papermaking wastewater should focus on improving the recycling water rate, reducing water consumption and wastewater discharge, and actively explore various reliable, economic and effective treatment methods that can make full use of the useful resources in wastewater. For example, the flotation method can recover the fibrous solid matter in white water, the recovery rate can reach 95%, and the clarified water can be reused; the combustion method can recover the sodium hydroxide, sodium sulfide, sodium sulfate and other sodium salt combined with organic matter in black water. Neutralization method can adjust pH value of wastewater; coagulation sedimentation or flotation method can remove suspended solids in wastewater; chemical sedimentation method can decolor; biological treatment method can remove BOD, which is more effective for kraft paper wastewater; wet oxidation method is more successful in treating sulfite pulp wastewater. In addition, reverse osmosis, ultrafiltration and electrodialysis are also used at home and abroad