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The pre-treatment process has a significant place in the electroplating process, metal surface treatment agent used as electroplating increasingly stringent requirements and innovation. The metal surface treatment agent wastewater generated by the process, and the most difficult to deal with in terms of COD. Substances containing heavy metals and other inhibiting the growth of microorganisms in the wastewater, biochemical processing unstable, and therefore the purpose of this paper is to study use of physical and chemical processes, ie coagulation as pretreatment combined with activated carbon adsorption, Fenton oxidation, potassium permanganate oxidation coagulation treatment methods to get the best combination of technology removal of COD, to provide a reference for metal surface treatment agent production wastewater treatment. Coagulation pretreatment, the choice of the PAC (PAC), polymeric ferric sulfate (PFS) and lime [Ca (OH) 2] and other agents for coagulation tests found that lime the COD Cr the highest removal efficiency, when the lime dosing concentration of 1200 mg / L, COD Cr removal rate of 44.7%. Wastewater after coagulation, activated carbon adsorption, respectively, Fenton oxidation, potassium permanganate oxidation test. Activated carbon adsorption test # 4 activated carbon adsorption efficiency of COD Cr highest when # 4 activated carbon dosing concentration of 2400 mg / L, reaction time 60 min, of COD Cr removal rate of more than 60%; the Fenton oxidation test dosing quality than H 2 O 2 : the COD Cr = 1:1, the molar ratio of FeSO4: H 2 O 2 = 1:5, reaction when the initial pH of 4, and the reaction time of 150 min, after the reaction COD Cr removal rate was 35.1%; potassium permanganate excellent oxidation coagulation effect, and with the increase in dosage, COD Cr removal increases. The test found that the pH = 7 conditions, potassium permanganate optimum dosage of 30 mg / L, reaction time 60 min, the COD Cr removal rate of close to 50%. The best combination of order in a separate trial on the basis of a combination of tests, to arrive at the wastewater treatment coagulation and activated carbon adsorption oxidation. In order to reduce the amount of activated carbon, can be secondary activated carbon adsorption, and the second after adsorption of the activated carbon used for the raw water back for adsorption; the oxidation reaction, potassium permanganate is more lenient than the Fenton oxidation conditions, COD Cr removal higher is selected. According to the above results, the design of a treatment capacity of 40m 3 / day wastewater treatment station, influent average COD Cr 1.44 × 103 mg / L, and a processing COD Cr (activated carbon adsorption and coagulation) COD Cr 298 mg / L, secondary treatment (activated carbon adsorption and potassium permanganate oxidation coagulation) 93.2 mg / L, reached the provincial standard water pollutant emission limits \
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