Abstract：Chromatography integration is being widely used in the purification of hepatitis B virus surface antigen (HBsAg) expressed by recombinant Chinese hamster ovary cell line. The low final product recovery rate limits manufactory production and HBsAg vaccine application. Polyethylene glycol (PEG) precipitation is applied to improve HBsAg yield. The effects of PEG concentration, pH value and ionic intensity on PEG precipitation were investigated by orthogonal design of the experiments. Under the optimized conditions of 0.12 g/mL PEG6000, 4℃, pH 9.0, the recovery rate of HBsAg was up to 96.8% while the purification factor was 3.7. Furthermore, the macromolecular impurity and bovine serum albumin were effectively removed by PEG precipitation. The total recovery rate of HBsAg was improved to 41% and PEG could be removed by gel filtration chromatography in the final product.