The nanofiber based filtering media, made up of fibers of diameter less than 1000 nm, have been discovered as new filtering media for effective filtrations. The present study has been made of the influence of various process parameters on the fibrillation characteristics of Lyocell fibers which focuses on how the Lyocell fiber changes with the intensity of beating. Meanwhile the drainage properties and media properties of Lyocell fiber with different beating degree are characterized. The results show that the length, diameter, distortion and degree of fibrillation of Lyocell fiber changes obviously by beating, and a mass of nano-fibril appeared after intensive beating. The Lyocell fiber is cut off rapidly at first, and then fibrillateion starts to appear during the process of beating. At the same time, comparing with the length of the fiber, the beating degree of Lyocell fiber is more sensitive to the degree of fibrillation. What’s more, the drainage time of Lyocell fiber with strongly beating is over ten times than that of the original or ratherish beaten one; Comparing with the media made from original or light beaten pulp, media thickness made from the strongly beaten fiber decreases almost two times, tensile strength increases nearly four times, and air permeability decreases about seventy times.This study has shed some light on the major properties of Lyocell fiber and paves the way for further application of Lyocell fiber in filed of high precision filtration media.