The invention provides a heat tube. The heat tube comprises a lower header, an upper header, a heat exchange tube bundle and reflux tubes, and the heat exchange tube bundle communicates with the lowerheader and the upper header; the lower header is an evaporation end, and a condensation end comprises the upper header; a fluid absorbs heat and evaporates in the lower header and condenses in the upper header, and the condensed fluid returns to the lower header through the reflux tubes; the reflux tubes are connected with the end parts of the two sides of the lower header and the upper header; and an electric heating device is arranged in the lower header, the heating power of the electric heating device continuously reduces from the middle part of the lower header to the two ends of the lower header. According to the heat tube, the power of the electric heating device changes, so that the heating efficiency is further improved, and the heat exchange efficiency of the heat tube is improved.