Abstract: Based on analyzing the characteristics of high shear ratio, centrifugal pressure difference and mass transfer mechanisms in rotary tubular microfiltration membrane separators, the factors affecting the permeation ability were summarized into three essential factors: the structure permeation factor which increased with time and reflected the role of both membrane structure and irreversible membrane fouling, the reversible membrane fouling factor when the membrane tube was in stationary, and the enhancement factor produced by the rotation of the membrane tube. A relative enhancement factor which was the ratio by taking the permeation ability when the membrane tube was in stationary as a scale to measure the permeation ability in rotation was proposed to denote the degree of enhancement produced by the rotation of membrane tube. The relationship of the relative enhancement factor with the rotary Taylor number in different concentrations, different pressures and different mass transfer controlling mechanisms were investigated by experiment, and then the causes of its characteristics were analyzed.