Abstract: As the reliability of turret components of CNC machine tools will affect the machining accuracy of CNC machine tools， this paper takes the spiral bevel gears manufactured by a company as the research object and proposes an analysis method of gear structure parameters to explore the vibration causes. This method uses laser scanning reverse engineering technology，tolerance measurement technology，and equipment fault diagnosis noise analysis technology to digitally detect the engagement quality of spiral bevel gears based on the gear engagement theory. Noise audio of sample arc-tooth bevel gear and improvement arc-tooth bevel gear is extracted by experiment during the actual operation of arc-tooth bevel gear，and the noise spectrum of two pairs of gears is compared and analyzed to confirm the correctness and validity of the theoretical method. The results show that the main reasons for the noise of the sample arc-tooth bevel gear are too large modules，too few teeth and low coincidence，which will feedback and guide the design and machining，improve the meshing quality of domestic spiral bevel gears and the machining quality of machine tools.

Key words: CNC machine tool turret, spiral bevel gear, vibration noise, frequency spectrum analysis