In order to improve the clarity and stability of cider, membrane ultra-filtration technology was used for clarification. Box-Behnken response surface methodology (RSM) was adopted to study effect of the key parameters pressure, temperature and feeding velocity on membrane flux. The results indicate that the order of three factors effects on membrane flux are as follow: temperature, pressure, feeding velocity. The optimal levels for cider clearing were obtained, including pressure of 0.7MPa, temperature of 24℃, feeding velocity of 5.6mL/min. Under optimized conditions, the luminousness of cider is 98.72%, the membrane flux is 14.38L/(m2〖DK〗·h), and the flavor and quality of cider are satisfactory.