An activated-carbon crushing device comprises a bucket elevator, a stock bin, a support frame, a primary grinding chamber, a secondary grinding chamber, a screening chamber and a charcoal powder collecting can. The support frame is sequentially divided into four layers, namely a fourth layer, a third layer, a second layer and a first layer from top to bottom, the stock bin is arranged on the fourth layer, the primary grinding chamber and the secondary grinding chamber are arranged on the third layer side by side independently, the screening chamber is arranged on the second layer, the charcoal powder collecting can is arranged on the first layer, the outlet end of the bucket elevator is connected with the inlet of the stock bin, the outlet of the stock bin is connected with the inlet of the primary grinding chamber, the outlet of the primary grinding chamber is connected to the top of the screening chamber, the outlet of the secondary grinding chamber is connected to the top of the screening chamber, a return pipe is arranged on the side wall of the screening chamber, and the other end of the return pipe is connected to the top of the secondary grinding chamber. The activated-carbon crushing device is novel in design and ingenious in structure, accuracy in grinding can be improved by the aid of a double-grinding mode, and dust pollution can be prevented by the arrangement of a dust removal system.