The invention discloses a method and device capable of improving ceramic core removal efficiency. Firstly, according to the method, alkali liquor is used as core removal liquid, and clear water is used as a medium for regularly removing core removal products. The device adopting the method comprises an alkali liquor cavity, a clear water cavity, a reaction cavity and a pressure bearing cavity. During work, the alkali liquor is sucked back to the alkali liquor cavity through a vacuum air pump after being injected in the reaction cavity to react for a period of time, then, clear water is injected in the reaction cavity and violently boils at the moment, the core removal products attached to the surface of a core are removed through the boiling flushing force, then, the clear water is sucked back to the clear water cavity, the alkali liquor is injected to the reaction cavity again, and the steps are repeatedly executed till the core is completely removed. According to the type of device, pressure inside a system is kept constant through a pressure stabilization air pump. Because no pressure difference exits between the interior and the exterior of the reaction cavity, the wall thickness is decreased, and safety is improved. Because the core removal products on the surface of the core can be flushed away by injecting the clear water periodically, the core removal speed is substantially increased, and the method and the device can be used for removing the ceramic core of any complex structure.