0.2%，废水pH值为9.0时，COD去除率达56.24%。Polymerization aluminum chloride (PAC) and cationic polyacrylamide (CPAM) were used to treat potato starch wastewater. The cleaning efficiency of the chemical oxygen demand (COD) in the wastewater was also studied by changing the experimental conditions. In the orthogonal test, the optimal conditions were as follows: PAC addition 0.2%, CPAM addition 0.1%, and reaction pH value 9.0. The removal rate of COD was 56.24%. 