The small hole muffler consists of a straight tube with one end sealed and a housing, with many small holes drilled into both the tube walls and the housing. The principle of the small hole muffler is based on the spectrum of jet noise. By maintaining the total area of the nozzle unchanged and replacing it with many small nozzles, the spectrum of jet noise shifts towards high or ultra-high frequencies as the airflow passes through the small holes, significantly reducing the audible components in the spectrum, thereby minimizing interference and harm to humans.