Electric heating core of hair roller, electrothermal hair roller and method of heating electrothermal hair roller

The invention discloses an electric heating core of a hair roller, an electrothermal hair roller and a method of heating the electrothermal hair roller. The electric heating core of the hair roller comprises an electric heating element, a power cord electrically connected with the electric heating element and a casing. The casing comprises a handle and a cylindrical plug, the rear of the plug is fixedly connected with the handle, the electric heating element is mounted inside the plug, and the power cord is led out of the rear of the handle. The electrothermal hair roller comprises a roller and the electric heating core, the roller comprises a tube including an outer tube and an inner tube, the tube wall of the inner tube is connected with the tube wall of the outer tube, the plug of the electric heating core is plugged into a tube hole of the inner tube, and the tube hole of the inner tube is matched with the plug of the electric heating core in shape. When the hair roller needs to be heated, the electric he