Large tank welding seam polishing trolley

The utility model discloses a large tank welding seam polishing trolley which comprises a bottom plate support, a polishing mechanism, a translation driving mechanism and supports, the supports are vertically fixed to the upper surfaces of the two ends of the bottom plate support respectively, and a horizontal supporting beam is fixed above the bottom plate support and located between the top ends of the supports at the two ends. A horizontal moving mechanism is installed on the horizontal supporting beam, a grinding mechanism extending to the position below the center of the bottom plate support is arranged below the horizontal supporting beam, and the grinding mechanism is connected to the horizontal supporting beam through a horizontal translation driving mechanism. Rolling wheels are arranged at the bottoms of the two ends of the bottom plate support, a central shaft of each rolling wheel is in transmission connection with a movable driving motor, and at least one magnet is arranged on the lower surface o