U-shaped/W-shaped electric heating tube is made by installing heating wire into a seamless metal tube (carbon steel tube, titanium tube, stainless steel, and copper tube), filling in the remaining space with magnesia powder with good conductivity and insulativity, contracting the tube, and finally forming the tube into required shapes. Such tube has simple structure, high thermal efficiency, excellent mechanical strength, and superior adaptability to hostile environment. The product can be used to heat up various liquids and acid and alkaline salts; meanwhile, it is also applicable to heating and melting of low melting point metals (lead, zinc, tin, babbitt). If special specifications are required, we provide special design and manufacturing based on the drawings provided by customers.