High temperature resistance wire evenly distributed in the high temperature stainless steel seamless pipe, thermal conductivity and good insulating properties of crystalline magnesium oxide powder compact to fill in the gap section, this structure is not only advanced, high thermal efficiency and heat evenly, when the high temperature resistance wire in the current through the heat produced by the crystallization of magnesium oxide powder to the metal tube surface diffusion, and then passed to the parts or oil is heated, the heating purpose.