Abstract: Aiming at the problems of the accumulation of chips and build-up on the root of the fillet after the components were machined,which causes the gaps on the surface of the material to become tight and irrelevant fluorescents display, and easily leaded to missing inspection of defects.In this article,an experimental analysis on existing inspection case was conducted and the causes leading to the fluorescent trace indication of machining build-up edge were found out,and some relevant treatment measures were taken to avoid such problems.