Abstract: In the study of inertial confinement fusion, the boron cylindrical micro-target can be used as hohlraum filling material. In this paper, the boron cylindrical micro target was machined by electrical discharge machining (EDM) milling technology, and the dielectric is material which has higher carbon content and the electrode material is tungsten steel which has good electrical conductivity. The boron column size was characterized by OLYMPUS STM6 measuring microscope. The results show that dimension precision of diameter is less than 10 μm. The morphology of the sample was analyzed by scanning electron microscopy (SEM). The results show that the surface morphology of boron is unchanged. The surface conductive layer of sample was characterized by energy dispersive spectrum (EDS) analysis and X-ray energy spectrum (XPS) analysis. The results show that during the EDM milling process, because the dielectric breaks into free carbon and the electrode material is fused and deposited on the surface of the workpiece, the auxiliary conductive layer is formed. Through machining processing of the auxiliary conductive layer, the instantaneous high temperature causes the boron to melt and gasify, thus machining processing of the semiconductor boron is realized.