The invention relates to a polishing mechanism for machining of a cylindrical product. The polishing mechanism comprises a supporting plate. A carrying rotary seat connected with a carrying motor on the lower portion of the supporting plate is arranged on the supporting plate, a pressing device matched with the carrying rotary seat is arranged above the carrying rotary seat and matched with the carrying rotary seat through a pressing rotary seat, and a polishing wheel is arranged on the side face of the carrying rotary seat. A bearing seat is arranged on the supporting plate, a polishing rotary shaft connected with a polishing motor is arranged on the bearing seat, a driving wheel is arranged on the polishing rotary shaft, a polishing abrasive belt is arranged between the driving wheel andthe polishing wheel and matched with the carrying rotary seat, and the polishing wheel is connected with a feeding mechanism. The polishing mechanism for machining of the cylindrical product is provided with the carrying rotary seat driven by the carrying motor and provided with the pressing device with the pressing rotary seat as well, and then the carrying rotary seat and the pressing device are matched with the polishing abrasive belt making contact with the side face of the product and capable of moving so that continuous and automatic polishing can be achieved, and polishing uniformity and precision are greatly improved.