In view of the high concentration wastewater produced in a production process of company, which is difficult to be treated directly by conventional and simple biochemical methods, the hydrogen peroxide pretreatment process was added to the original wastewater treatment process. The operation results show that the combined process of hydrogen peroxide pretreatment and biochemical method can treat high concentration wastewater （ COD of raw water is up to 12 400 mg / L ）, and the effluent meets the acceptance standard of COD < 500 mg / L.