The NC machining is the most effective processing method of complex structure and high precision requirements of the parts with. The ball joint, with complex structure and high precision, is the key component of the oil and gas connection, hard to machine, and should be used in NC machining. The ball joint of NC machining parts drawing, including structure analysis of NC machining process, fixture and clamping scheme selection and programming parts etc.. Through comprehensive analysis of these aspects, completes the processing of ball joints in CNC milling machines.