摘要：The central region model (CRM) cyclotron is the experimental platform for the key technology study of a high intensity beam *** this paper we introduce the spiral inflector and central region designed for the CRM cyclotron,including the physical design,the numerical control machining and the installation precision control *** shape of electrodes is complex,and machining with a strict tolerance must be done by a numerical control machine tool with the number of its axles no less than *** electrodes of central region were finished by using 3-axle machine *** size of gaps between the ground and Dee tip is very important,a special device was made to guarantee the installation precision,and the error of gaps was controlled within±0.05mm.