In order to extend applied realms of back-scattered-electron (BSE)imaging technique in the nano-meter multilayer morphology observation，the basic principles and applications of the BSE images in nano-multilayer characterization are described from three aspects：analytical accuracy，maximum resolution and detection

angle. BSE imaging is used to study the composition changes in the micro areas of nanomultilayer so as to understand the composition and structure characteristics of samples in a short time and to provide a handy and effective analysis method for the multi-layer structures of nano-multilayer. Meanwhile，the discussion of this technology will help physics majors better understand the physical mechanism of backscattering phenomenon，and help materials majors better apply this characterization technology.