Laying electric heating tubes, compared to electric heating wires, is more widely used in various household appliances and industrial electric heating equipment today. The structure consists of a metal tube with pre-wound spiral wires and焊接引出棒 inserted inside, and magnesium oxide powder with good thermal conductivity and insulation properties is tightly filled in the gap between the spiral wires and the tube. This is then formed through a shrinking tube process and sealed with an insulating glue. This type of metal electric heating element can heat air, metal molds, and various liquids (water, oil, acidic or alkaline corrosive liquids). The electric heating tube features a simple structure, high mechanical strength, can be bent into various shapes, long service life, good energy-saving properties, easy installation, non-polluting, and high thermal efficiency.