A type of cationic polyacrylamide (CPAM) prepared in laboratory combined with polyaluminum chloride (PAC) was applied in flocculation of simulated kaolin wastewater. The Box?Behnken mathematical relational model between transmittance and affecting factors was established, and the conditions of flocculation performance were optimized. The optimum flocculation conditions were determined as follows: PAC dosage of 38.39 mg/L, CPAM dosage of 1.09 mg/L, rapid mixing time of 9 min and pH of 5.18. Under these optimized conditions, the transmittance of processed water arrived at 99%. The results confirmed that, compared with separately application, flocculation through CPAM combined with PAC in low dosage can be effectively. Simultaneously, dense flocs were generated in flocculation, which have a strong ability to resist shear and fast sedimentation speed.