The invention discloses an automatic coating device of adhesive for a cold bonding joint of a rubber conveying belt. The device comprises a screw driving motor, a screw driving transmission, an adhesive holding box and a slide block; an air pump driving motor is mounted above the screw driving motor; a device frame is arranged above the screw driving transmission; a device worktable is mounted above the device frame; a cleaning wheel driving motor is mounted above the device worktable; the adhesive holding box is connected above the cleaning wheel driving motor; an adhesive nozzle is mounted below the adhesive holding box; a cleaning wheel bracket is mounted below the adhesive nozzle; a cleaning wheel communicates below the cleaning wheel bracket; the slide block is mounted above the cleaning wheel; and a control switch is mounted above the slide block. The device has the following beneficial effects: the adhesive can be uniformly coated on the bold bonding joint; the adhesive cannot be wasted; and meanwhile, the strength of the cold bonding joint is improved.