The invention relates to a polishing device, in particular to a rotary polishing device for a household water purifier stainless steel cylinder. The technical problem to be solved by the present invention is to provide a rotary polishing device for stainless steel cylinders of household water purifiers that can be used for polishing various types of cylinders and has a good polishing effect. In order to solve the above technical problems, the present invention provides such a rotary polishing device for household water purifier stainless steel cylinder, which includes a support frame, a first motor, a clamping mechanism, a first fixing rod, a first bearing seat, etc.; The middle of the bottom of the frame is connected with a first motor, the top of the output shaft of the first motor is connected with a clamping mechanism, the back side of the top of the support frame is connected with a connecting plate, the connecting plate is located at the rear side of the first motor, and the top front of the connecting plate is connected with a support pole. In the present invention, the top of the cylinder body is driven by the pressing plate by rotating the first support rod, and then the handle is turned, thereby driving the grinding plate to move to the middle to clamp the cylinder body tightly, and then start the second motor.