The invention discloses an integrated rotary operation device for an automobile silencer. A first shaft body is in shaft connection with an output shaft of a reduction motor. A second shaft body is rotatably arranged on a shaft seat. A front silencing pocket and a rear silencing pocket of the silencer are clamped onto a first mounting plate and a second mounting plate. The end of a first cylinderis provided with an air inlet choke plug used for blocking an air inlet. The end of a second cylinder is provided with an air outlet choke plug used for blocking an air outlet. A spraying device is located on one side of a turnover frame. The spraying device is provided with a plurality of spray nozzles, and the spray nozzles requirement located above joints of the silencer and spray soap water. An airtightness detector is located on one side of the turnover frame and communicates with the silencer through the air inlet choke plug and/or the air outlet choke plug. A character carving machine is located on one side of the turnover frame and can extend to the outer wall of the silencer to conduct character carving. The integrated rotary operation device can conduct airtightness detection onthe joints of the silencer and conduct character carving on the outer wall of the silencer.