The dynamic performances of ultrasonic vibration system are the key facts decided the manufacturing precision of the ultrasonic compound micro-fine electrical-Machining, that is ultrasonic compound micro-fine EDM&ECM (electro-discharged machining and electrochemical machining). The finite element method is used to analyze the dynamic performance of the ultrasonic vibrating system, the finite element analysis package ANSYS is applied to optimize the structure design of the piezoelectric transducer vibration system. A serious of optimization tests are carried about the ultrasonic compound micro-fine electrical-Machining, a few of micro-fine structures are machining by the optimization processing parameters. It is proved that the system's optimization designing can improve the machining performances by increasing machining process's reliability and stability, and the ultrasonic compound micro-fine electrical-machining would have better machining precision and higher productivity for to machine the materials difficult to machining and the special shape's structures.