The dynamic error of spindle has an important influence on machining accuracy. The dynamic error of spindle was tested and analyzed.The concept of dynamic error of the spindle was introduced ,and dynamic error analyzer of the spindle was used to collect the dynamic errors, including radial average errors, radial asynchronous errors, axial average errors ,axial asynchronous errors and axial minimum clearance. Three same type vertical machining centers were measured under different rotating speeds respectively,and the measurement results were compared and analyzed. At the rotating speed of 7 500 r/min, Radial asynchronous errors of three vertical machining centers are 70, 15 and 15 μm respectively. After the rotating speed increased to 6 000 r/min，the minimum radial clearance of the spindle increases significantly. The results show that the dynamic accuracy of the spindle was affected by the working condition and rotating speed of the machine.In the case of highspeed rotation ,the radial minimum clearance increases obviously. To ensure the quality of machining,the rotating speed should be arranged according to the working condition reasonably when processing.