This paper is mainly concerned about the machining of high-precision deep holes with small diameter in the cone of optical equipment.According to the characteristics and the technical requirements of the parts,the problems in the parts processing using the traditional method was analyzed and the method of WEDM-LS was selected to manufacture the parts.On the basis of the study on WEDM-LS characteristics and process specifications,by a large number of experiments,the effective processing measures and parameters were summarized.The processing result is satisfactory after tested by coordinates measuring instruments.In a word,these processing methods and parameters can be widely applied on other parts of similar materials and structures,and a new method for the processing of high-precision minor-diameter deep holes is brought up.