Polyimide (PI) film etched by electron beam (EB) to produce PI micron-hole separation membrane combined with the methods of masks and oxygenation corrosion was studied in this paper. The effect of the absorbed doses, corrosion time and corrosion temperature on the corrosion speed of irradiated PI were discussed. The results showed that the corrosion speed of irradiated PI grew up with increasing the corrosion temperature, corrosion time and absorbed dose gradually. The analysis of infrared spectroscopy (IR) indicated that the main chain of PI molecules was broken by EB to certain extent. It meant the molecule weight of PI turned small and PI film was eroded easily by oxidation solution. In the EB etching process, a piece of lead mask with micron-holes was covered on the PI film and was etched by EB. And then the irradiated PI film was eroded by the solution of H,2,SO,4, and K,2,Cr,2,O,4,. A piece of PI micron-hole separation membrane was gained by this technology.