The invention relates to an ore breaking device which comprises a thumping device and a workbench; the thumping device is provided with a fixing plate; the workbench is located below the thumping device; electromagnetic movable heads and a thumping movable head are arranged at the lower part of the thumping device; electromagnetic fixed heads located under the electromagnetic movable heads and a thumping fixed head located under the thumping movable head are arranged on the workbench; when each electromagnetic fixed head and the corresponding electromagnetic movable head have unlike polarities, the thumping device moves downwards through a guide rod vertically fixed between the workbench and the fixing plate, and at the same time, the thumping device drives the thumping movable head to downwards thump ore placed on the thumping fixed head; and when each electromagnetic fixed head and the corresponding electromagnetic movable head have like polarities, the thumping device drives the thumping movable head to move upwards to a normal position. The workbench further comprises cams, a motor and spring devices, the spring devices are located on the cams, the motor drives the cams to rotate and further controls the spring devices to make up-and-down reciprocating motion. Compared with the prior art, the ore breaking device can continuously and efficiently break the ore and the granularity after the breaking is more uniform.