Abstract: This article on ceramic substrate by using the method of magnetron sputtering plating on a thick layer of titanium,using different methods for surface treatment of metal titanium layer,processed substrate in a microwave plasma chemical vapor deposition chamber,in the same diamond film deposition was prepared under the condition of different microns. To different membrane of microscopic surface morphology,structure comparison research; To different membrane using diode structure to test the performance of their field emission electron,a thorough study on the mechanism and the launch. Final analysis of different methods for treatment of substrate,the micro polycrystalline diamond film growth,and the influence of the field emission properties.