Cellulose acetate (CA) membrane was prepared by liquid-solid phase inversion method with cellulose acetate, acetone, N-methylpyrrolidone (NMP) and polyethylene glycol 400 (PEG-400) as raw materials. The structure and morphology of CA membrane were characterized. At room temperature, the prepared CA membrane was used to treat deionized water and 500 mg/L polyethylene glycol 600 under the pressure of 0.1 MPa in its water flux and rejection rate, respectively. The effects of mixed solvent content, reaction temperature and PEG-400 content on the separation properties of membrane were examined. The results showed that under the conditions of NMP and PEG-400 contents of 60% and 6%(w), and reaction temperature of 60℃, the prepared CA membrane surface was smooth and the pore size distribution uniform, its water flux was 212.87 L/(m2×h), and the rejection rate 87.67%.