The invention discloses a novel type sulfur phosphorus pig iron used for aluminium electrolysis, wherein, the compositions of the pig iron according to weight percentage is as follows: C: 1.8 to 3.8 percent, Si: 1.8 to 2.8 percent, Mn: 0.20 to 1.5 percent, P: 0.1 to 0.8 percent, S: less than 1.0 percent, Fe as the rest and other impurities: less than or equal to 1 percent); when in tapping, the hot metal is supplemented in the proportion of additives (0.5 percent to 1.0 percent of hot metal). The constituents of additives according to weight percentage is as follows: RE: 2.0 to 4.5 percent, Ca: 2.5 to 4.5 percent, Ba: 1.5 to 3.5 percent, Al: 2.0 to 3.5 percent, Bi: 1.0 to 2.5 percent, Mn: 1.5 to 4.5 percent, Si: 35.0 to 45.0 percent, Fe as the rest and other impurities:less than or equal to 1 percent. The use of additives, the change of constituents range of high S, C, Si, Mn, and S substituting P leads to that the chemical constituents are more reasonable, by tested, Fe-C voltage drop is 10 to 20mV lower than that of traditional P-Fe, pressure-disengaging force reduces by 5 to 22 percent, and desulfurization rate is 6 to 25 percent.