The invention discloses a grinding machine for spanners. The grinding machine comprises a rack, a spanner falling device is arranged on the rack and used for containing the spanners, and a conveying device is arranged on one side of the spanner falling device and can be used for taking the spanners away from the spanner falling device and conveying he spanners. A rough grinding device and a fine grinding device are sequentially arranged at the positions, in the conveying direction of the conveying device, of the rack and used for grinding the spanners. Meanwhile, a control box is further arranged on the rack and used for controlling action of all the devices. Because the spanner falling device, the conveying device, the rough grinding device, the fine grinding device and the control box are arranged on the rack, operation of all the devices is controlled through the control box, the spanners are ground in a full-automatic mode, manual grinding is abandoned, and grinding efficiency is greatly improved; meanwhile, the rough grinding device and the fine grinding device are provided with two grinding heads and two fine grinding heads respectively, so that two side faces of each spanner are ground at the same time, grinding efficiency is further improved, and the social competitive power of an enterprise is improved.