The invention provides an overheat protection controller component used in a liquid heating vessel. The overheat protection controller component comprises a controller body, the upper surface of whichis equipped with a monolithic conjunct double-actuation thermosensitive double-metal actuator that is provided with two conjunct and relatively independent actuating units on a piece of double-metalplate. An internal tongue of each actuating unit can actuate downwards under the overheat condition. The controller body is also provided with two sets of switch connection points. Each set of switchconnection points are matched with one internal tongue of the corresponding actuating unit. When the internal tongue actuates downwards, the internal tongue can open one corresponding set of switch connection points and switch off the power supply of the liquid heating vessel that is a heater. The overheat protection controller component used in the liquid heating vessel has the characteristics ofreliable overheat protection as well as exact and constant actuation.