Aiming at solving the problem which was caused by the high-speed mechanical spindle vibration that could damage elements manufacturing precision and surface quality under the working condition, the influence coefficient method is applied for spindle on-line dynamic balancing. The experiment platform was erected. The mechanical spindle resonance speed was discovered by using the electromagnetic drive balancing device under different working conditions with dynamic balancing effects. The double influence coefficient method was adopted after entering the flexible stage of the spindle from critical speed. In order to display the spindle vibration accurately, the spindle vibration at both orient and vertical direction were simultaneously respectively detected. The experimental results indicate that the double plane coefficient online dynamic balancing possess more accuracy than that of single plane coefficient. The spindle vibration amplitude is decreased significantly and the balance efficiency improved. Such achievements of experiments provide references of regulation strategies for the online dynamic balancing control of high speed machine spindle.