In order to study the change of each phase and the influence of single oxide during the consolidation of pellets. A systematic thermodynamic calculation was carried out through the phase diagram to study the influence of five oxides (CaO, SiO2, Fe2O3, Al2O3 and MgO) on the phase equilibrium of the hematite pellet system. The results show that the content of CaO has the most significant effect on the content of liquid phase and SPINA. There are critical values for the influence of SiO2 and CaO on the Ca3Fe2Si3O12 phase, which are 3.5% and 3.0%, respectively. Through in-situ heating experiments, XRD-Rietveld and SEM-EDS, the macro morphology and phase composition of the hardened samples were compared and analyzed. Finally, a multiple regression model is used to predict the liquid content of hematite pellets, which is effective in predicting the phase component.