This standard specifies a chloride ion correction method for the determination of chemical oxygen demand (COD) in wastewater from high chlorine and high ammonia, which is suitable for the detection of wastewater generated during the production of refining catalysts and related materials. This method is suitable for wastewater with a chloride ion concentration not exceeding 2000 mg/L, an ammonium Ion concentration not exceeding 1000 mg/L and a COD greater than 50 mg/L, providing a standardized detection method for wastewater treatment in related enterprises.