Centrifuge is a device for separating heterogeneous liquid system by centrifugal force. According to the difference of sedimentation coefficient, mass and density of substances, the method of separating, concentrating and purifying substances by using strong centrifugal force is called centrifugation. Generally speaking, the centrifuge speed above 30000r/min is called overspeed centrifugation. Centrifugation technology, especially ultracentrifugation technology, is an indispensable means in molecular biology, biochemical research and industrial production.