The utility model provides an electric-heating plaster for treating the swelling and inflammation of the breast, which consists of a sector electric heater and a sector plaster sheet, wherein the sector electric heater consists of a heat-preservation layer, an electric-heating wire, a heat-storage layer and a power-source interface, and the electric-heating wire is inserted between the heat-preservation layer and the heat-storage layer, two ends of the electric-heating wire are connected with the power source interface which is arranged on the edge part of the heat-preservation layer, and the sector plaster sheet is adhered to the heat-storage layer of the sector electric heater. Compared with the traditional black plaster, by utilizing a carrier to carry the plaster, the electric-heating plaster for treating the mastitis or swelling of the breast has good effect on preventing the flow and the pollution, and not only can ensure the hot-pack active area, but also can prevent the heated plaster from flowing out and polluting the clothes; moreover, since the thickness of the plaster carrier is uniform, the application quantity of the drug is greatly reduced; under the same treatment area, the application quantity of the drug is only one tenth of that of the traditional plaster; and moreover, with double-sided application and the physical therapy effect of the electric heating penetration, the healing effect is ten times of that of the traditional plaster.