The invention discloses a silencer. The silencer comprises a shell, a front end cover, a rear end cover, a first partition plate, a second partition plate, a third partition plate, a gas inlet pipe, a first high-frequency pipe, a gas outlet pipe and a second high-frequency pipe. The gas inlet pipe and the first high-frequency pipe are coaxially connected into a whole. The gas outlet pipe and the second high-frequency pipe are coaxially connected into a whole. A plurality of first through holes are evenly distributed along the pipe wall of the gas inlet pipe. A plurality of second through holes, a plurality of third through holes and a plurality of fourth through holes are sequentially and evenly distributed along the pipe wall from the end of the gas outlet pipe to the joint of the gas outlet pipe and the second high-frequency pipe. Exhaust gas flow enters the gas inlet pipe, high-frequency noise is eliminated through the first high-frequency pipe, resonant silencing is conducted on medium-frequency noise of the gas flow through the first through holes in the gas inlet pipe, low-frequency noise is eliminated through a narrowed gas inlet pipe opening, low-frequency noise, medium-frequency noise, low-frequency noise and medium-frequency noise are sequentially eliminated through a gas outlet pipe expanded opening, the second through holes, the third through holes and the fourth through holes in the gas outlet pipe, high-frequency noise is further eliminated through the second high-frequency pipe, and therefore noise of all frequencies is effectively eliminated, the silencing range is wide, and the noise reduction effect is good.