The present invention provides a silencer, including: a silencer housing having an annular plate-like structure, with an annular mounting chamber formed therein; a silencing pad disposed in the mounting chamber; and a positioning portion disposed on the silencer housing and used for fastening the silencer housing. The silencer according to the embodiment of the present invention has an integrated structure, and can desirably avoid the problem of mounting unflatness in a separated structure. Moreover, the silencing pad therein is disposed to surround the entire silencer, which can provide a sound absorption and noise reduction effect more efficiently.