Based on the Finite Element Method (FEM) analysis, the vibration laws of ultrasonic vibration internal grinding system shaft were revealed, and the optimal structure of parts of the ultrasonic vibration internal grinding system shaft was designed based on the above analysis. The testing method of using Laser Doppler Vibration Tester for ultrasonic vibration internal grinding shaft system was given, and the vibration characteristics of the shaft system were studied by testing. The result of optimal structure design of ultrasonic vibration internal grinding system shaft is proved, and the prototype of ultrasonic vibration internal grinding head is manufactured.