The winter in southern China is very cold,along with high humidity. Regional ice coating problem often appears in the long distance high voltage transmission lines,which may lead to serious power accidents such as tower collapse. A new direct current (DC) ice-melting device with series-parallel switching of rectifier bridge is studied to avoid widespread power outages. Based on the conventional 12-pulse DC ice-melting device,a new DC ice-melting topology is proposed through principle analysis,parameter design and simulation verification,and it simultaneously meet the high current demand for wire melting and the high voltage demand for ground wire melting. Compared with the conventional 12-pulse DC ice-melting device,the new DC ice-melting topology is able to select half-capacity transformer and half-current thyristor,which significantly reduces the equipment costs. Meanwhile,the harmonic current injected into the system decreases effectively when operating in high current output mode,so as to reduce the voltage distortion of the connected system. The new DC ice-melting device with the function of series-parallel switching of rectifier bridge is able to reduce the equipment costs and improve the system voltage quality when the DC ice-melting device is put into operation.