Landfill leachate has become a difficult problem in the current water treatment field due to its complex composition, high concentration of COD and NH3-N, and large changes in water quality and quantity. At the same time, leachate is a derivative of waste treatment. The proper treatment of leachate is an important indicator for evaluating waste treatment projects. Shanghai Laogang Landfill uses advanced ozone advanced oxidation combined process to treat the waste concentrate. The treatment scale is large and the degradation effect is remarkable.