The invention belongs to the technical field of electric heating tube manufacture, and relates to an electric heating tube using hexagonal boron nitride or mixture of hexagonal boron nitride and magnesium oxide as a heat conducting material, in particular to a mixed heat conducting material for a novel electric heating tube. A main body structure comprises a metal tube body, a mixed filler, a resistance wire and accessories comprising a fixed plate, porcelain beads, sealant, a plastic plug, a leading-out bar, a terminal electrodes and screws; a cavity structure of the metal tube body is invariantly bent into a circular, elliptical or spiral geometric structure; parallel structures at two end sections of the metal tube body are fixed on the fixed plate in an interval penetration mode, and fixed screws are arranged at two ends of the fixed plate; and the resistance wire is fixed and electrically connected on the central axis of the cavity of the metal tube body and parallel to two end points on two sides of the tube wall, and the mixed filler is filled between the resistance wire and the side wall of the metal tube body. The electric heating tube has the advantages of high stability and heat conducting efficiency, high-temperature softening prevention in inert gas, long service life, high quality, good insulating property, low dielectric constant and dielectric loss, and safe use.