The spiral electric heating wire and the lead out rod are located in the center of the metal protective sleeve. Its manufacturing process involves threading the spiral electric heating wire into seamless steel pipes, copper pipes, or aluminum pipes. The gaps between them are evenly filled with insulating and heat-conducting oxide media, such as crystalline magnesium oxide powder (which can also be aluminum oxide or clean quartz sand), through a multi tube filling machine. Then use a pipe shrinking machine to shrink the diameter of the pipe, making the oxide medium dense (density above 3.3g/cm3), ensuring that the electric heating wire is isolated from the air, and the center position does not deviate and collide with the pipe wall. This way. The heat output per unit area can increase by more than ten times. The service life can also be correspondingly increased to over 10 years. Compared with electric heating elements with the same amount of heat, tubular electric heating tubes can save 5% of electric heating materials and achieve a thermal efficiency of over 90%.