Abstract: Separation process was investigated with 3-tube polyethylene microfiltration membrane based on the difference in concentration，operation pressure and inlet arrangement. Results indicated that the 3-tube membrane showed characteristics of higher permeation flux and less energy consumption when the concentration was 0.25%. The permeation flux with tangential inlet was 2 times of that with radial inlet. An optimum operation pressure was observed for the rotating flow of tangential inlet when the concentration was 0.5%.