The heating tube is a high-temperature and corrosion-resistant tube. There are spiral heating wires in the center of the heating tube. The gaps in the heating tube are filled with electrical grade magnesium oxide powder with good thermal conductivity and insulation. The two sections of the heating tube have insulating terminals. , There is a terminal in the middle. When the heating wire has current passing through, it will generate heat energy, and the heat energy will be transferred to the surface of the heating tube through the electrical grade magnesium oxide powder, and then conducted to the corresponding electrical products. This structure has high thermal efficiency, fast temperature rise, uniform heating, and good stability. When the heating tube is energized and heated, the electrical grade magnesium oxide powder is insulated, and the surface of the heating tube is not charged, so it is safe and reliable to use.