It is aimed at an enterprise production capacity of high -speed high -precision computer numercial control (CNC) vertical milling machine internal structure for dynamic characteristics test. Especially for different locations of the machine tool structure to carry out the dynamic characteristics of a series of testing work, the modal parameters, such as for frequency and vibration model were gotten. Eventually finding from combined test results that the weak link of the machine was the connected position of the saddle and the base，and machine overall layout was not reasonable, and the center of gravity was on the high side. Two respects of machine tool structure system dynamic characteristics test method and process are stated, including the experimental modal analysis test and machine tool cutting vibration test.