Abstract: To solve the big bulk, high cost and short life span problem of current vibration tapping and reaming system , and to promote application of the high performance vibration tapping and reaming technology, they proposed a wedge type torsional vibrator, which is of much smaller pressure angle, more compact,and which is symmetry in construction and easy to be fabricated. They obtained its output movement constraint equations, its cam curves' equations and synthesis methodology. They also gave an example to prove the validity of the equations. The vibrator can be widely applied to vibration tapping and reaming process .