Boron nitride materials have some excellent features, such as high temperature resistance, chemical resistance, good electric performance and radiation resistance . Along with the development of science and technology, boron nitride materials are made into coating widely, put it in the surface of metallic materials or non-metallic materials, can extend their service life significantly[1]. Atomic force microscope (AFM) is widely used for nanoscale morphology characterization and submicron scale structure material, simple sample preparation is its advantage. [2] Based on the domestic boron nitride coating as the research background, using AFM simulate the surface nanostructures of three dimensional, and evaluate the flatness of boron nitride ceramic coating which made by plasma spraying method and chemical vapor phase precipitation method respectively. The results show that the coating prepared with plasma spraying is more dense, surface flatness is smaller, surface roughness uniformity is better.