The invention discloses a grinding device. The grinding device comprises a grinding machine, a feeding pipe, a ball adding device and a control device, wherein the grinding machine is provided with a feeding port. The feeding pipe is connected with the feeding port. The ball adding device is internally provided with a cavity for containing grinding medium, and is provided with an inlet and an outlet which are respectively communicated with the cavity, and the inlet is connected with the feeding port. The control device is arranged at the outlet so as to open or close the outlet. According to the grinding device disclosed by the embodiment of the invention, the ball adding device and the control device are arranged, the outlet of the ball adding device is connected with the feeding port of the grinding machine, and the control device controls opening or closing of the outlet, so that the grinding medium can be filled when the grinding machine is in normal operation, continuous operation of the grinding machine is guaranteed and further the normal and continuous operation of the grinding machine on the production line is guaranteed.