Pulsed high energy density plasma (denoted as PHEDP), which is generated by using a coaxial gun, is characterized by high temperature, high energy density, high velocity, etc.This technique possesses several features, such as low deposition temperature (even under room temperature), high deposition rate and high energy efficiency.It is quite convenient to fabricate nanocrystalline or amorphous hard films by PHEDP.The broad transition layer between film and substrate is favorable for strong adhesion.In this work, the principles of PHEDP, as well as its application in films deposition are described.The application results of PHEDP films in cutting tools for subway construction were introduced.It reveals that the hard films prepared by PHEDP are feasible as the protection layer of the cutting tools, which can significantly prolong their service life.