The invention provides a self-resistant type electric soldering iron comprising a handle, a heating module and a soldering iron head. The lower portion of the hating module is connected to the soldering iron head in a transition manner, the heating module is sleeved with a cylindrical tin storage box, the lower portion of the tin storage box is provided with a conical bottom edge, an annular cavity is arranged between the tin storage box and the heating module and is provided with solder inside; a vertical tin discharging groove is arranged in the lower portion of the housing of the heating module and conical transition connection position, one end of the tin discharging groove extends into the annular groove, and the other end is machined to the fitting position of the soldering iron head. When the electric soldering iron is used, the solder is preheated and liquefied and flows to the soldering iron head from the tin groove automatically; thus, a person can operate the electric soldering iron with single hand more conveniently.