In order to obtain the machining method of the large diameter superalloy adjusting ring, the machining methods of turning, grinding and CNC milling were used to process the thickness of adjusting ring. The clamping location method of three machining methods was introduced. While ensuring the dimensional accuracy and controlling the deformation, the key technical points and advantages and disadvantages of the three machining methods were compared in detail according to the actual situation. It is determined that CNC milling is the ideal processing method. CNC milling method solves the problem of large number of spare parts of the large diameter superalloy adjustment ring,large capital occupation and long maintenance period and high cost due to long purchase period.The CNC milling method realizes the repeated use of adjusting ring,which greatly saves the cost. This study provides a good reference for the end face machining of similar largediameter disk parts with hard to machine materials.