The capacity of a pulp and paper plant in China is 14,000m3/d. Due to the quality of incoming water fluctuates greatly, the removal rate of biological system is unstable. To improve the impact resistance of biological system and reduce the concentration of COD. The plant added Novozymes BioRemove 5150, Novozymes BioRemove 1650 and Novozymes BioRemove 5600 to cultivate the dominant bacteria which can degradable rapidly. Through Bioaugmentation, the endurance of impact resistance of biological system increases and the system can remove organic matter. The COD removal rate increased from 61.4% to 80% after a month of seeding.