The invention relates to a cleaning device, in particular to a cleaning device for the outer wall of a flowerpot for a garden. The technical purpose is to provide the cleaning device which can clean the outer wall of the flowerpot thoroughly, prevent water from being splattered on the body of a worker and is for the outer wall of the flowerpot for the garden. According to the technical scheme, thecleaning device for the outer wall of the flowerpot for the garden comprises a base plate, vertical rods, an arc rod, slide sleeves, fastening bolts, connecting rods, a circular ring plate, a drivingmotor, a rotary shaft, a fixed block, a guide rod, guide sleeves, springs and the like; the vertical rods are installed at the left and right sides of the top of the base plate, the arc rod is installed between the tops of the vertical rods at the left and right sides, the slide sleeves are arranged on the vertical rods, and the fastening bolts are arranged in the middles of the outer side facesof the slide sleeves at the left and right sides. According to the cleaning device, through the function of the driving motor, hairbrushes can comprehensively clean the outer wall of the flowerpot; through a water spraying device, the water can be sprayed onto the outer wall of the flowerpot and the hairbrushes, and then the hairbrushes more thoroughly clean the flowerpot.