The invention provides a heat pipe. The heat pipe comprises an upper header, a lower header, coiled pipes and a backflow pipe; each coiled pipe is communicated with the lower header and the upper header; the lower header is an evaporation end; a condensing end comprises the upper header and at least part of each coiled pipe; fluid absorbs heat in the lower header to be evaporated; after heat exchanging is performed through at least part of each coiled pipe and the upper header, the fluid is condensed in the upper header; the condensed fluid returns to the lower header through the backflow pipe; one or more coiled pipes are arranged; each coiled pipe comprises a plurality of arc-shaped heat exchanging pipes; the end portions of the adjacent heat exchanging pipes are communicated so that theheat exchanging pipes can form a series-connection structure; an electric heating device is arranged in the lower header; and the heat pipe further comprises a temperature control system which is used for controlling the temperature of steam in the heat pipe. According to the heat pipe, by arranging a controlling device, the actual requirements can be better met in the using process of the heat pipe, a user can control the application temperature of the heat pipe as required, the overheating or supercooling phenomenon generated when the temperature of a traditional heat pipe cannot be well controlled is avoided, automation of a heat pipe device is further achieved, and universality of the application field of the heat pipe device is further achieved.