The electrospun Carbon nanofiber membrane is prepared by setting electrospun PAN fiber as the precursor and subjecting it to pre-oxidation, carbonization, graphitization processes.It has a diameter of 100 to 200 nm, which is 20 times finer than regular carbon fiber. Its specific surface area increases by over 20 times while its cross-section area increases by over 400 times, compared to regular carbon fiber. These changes in the microscale specifications brings the materials a series of extraordinary properties. It has wide application value and can be found applications in fields, such as high strength composite material, electrically conductive composite material, electromagnetic shielding, electrodes in electrochemistry, catalyst carrier, separation and filtration, heating unit, gas diffusion layer in fuel battery, etc.