The research studies the influence of different coated films on flank wear through commercial milling test. The milling tools with three distinct coated films (CVD DLC, PVD DLC and TiN) are observed by Scanning Electron Microscope (SEM). Combined with Nano-indentation test, the material properties of different coatings on WC tool is provided to help knowing the improvement in tool life of distinct coated film. Diamond probe of atomic force microscope(AFM) is used to simulate a hard tor on work piece to carry out scratch experiment when analyzing the ability of wear resistance. The wear behavior of coating will be explained by the results of micro-test.