Based on high frequency vibration cutting theory, a kind of three-degree of freedom (3-DOF) parallel machine tool with ultrasonic longitudinal vibration drilling device for micro holes was designed, which was composed by ultrasonic longitudinal vibration drilling device and 3-DOF parallel machine tool. The results show that high rotary and feed movement of machine tool can be achieved easily, which afford advantageous condition to precision and ultra-precision machining of micro holes in all soft materials. It can improve the machining accuracy and surface quality of micro holes. 