This paper introduces the composition of CNC machine tools and the classification of vibration. Based on the method of vibration diagnosis and the sensors, data acquisition instrument and signal analysis software produced by China Orient Institute, self-designed a high precise and portable vibration detection system. By this system, we can detect the engraving spindle of the shaped stone CNC machining center which own school developed, and analyze the possible causes of vibration. Figures out that the detection system is an effective testing equipment for quickly identifying the vibration source of machine tools. It plays an important role in providing the basis for structural dynamic design, guaranteeing the machining accuracy and improving the machine’s service life.