A de-icing device with wattless current injected in the end of a transmission line belongs to the field of high voltage power transmission systems. The invention aims at solving the problems of no forming equipment for a high-capacity adjustable inductor and large equipment investment by adopting a capacitance compensation inductance negative adjustment de-icing method. Two ends of the transmission line are respectively provided with a first isolating switch and a second isolating switch. The de-icing device also comprises a near-end de-icing isolating switch, a distant-end de-icing isolatingswitch and a reactive power compensator which is connected with one end of the near-end de-icing isolating switch. The connection point of the first isolating switch and the near end of the transmission line is connected with the other end of the de-icing isolating switch. The connection point of the second isolating switch and the distant end of the transmission line is connected with one end ofthe distant-end de-icing isolating switch, the other end of which is connected with a secondary bus of a distant-end transformer. The de-icing device is used for de-icing of high voltage lines.