Electric-furnace smelting has become the dominant process for the production of the titanium slag from ilmenite in China. The crystallization behaviors of anosovite and silicate crystals in the high CaO and MgO titanium slag were studied to insure smooth operation of the smelting process and the efficient separation of titanium slag and metallic iron. The crystallization behaviors were studied by a mathematical model established in this work. Results show that the crystallization order of anosovite and silicate crystals in high CaO and MgO titanium slag during cooling is: Al₂TiO₅ > Ti₃O₅ > MgTi₂O₅ > MgSiO₃ > CaSiO₃ > FeTi₂O₅ > Mn₂SiO₄ > Fe₂SiO₄. Al₂TiO₅ and Ti₃O₅ have higher crystallization priority and should be responsible for the sharp increase in viscosity of titanium slag during cooling. The total crystallization rates of anosovite and silicate crystals are mainly controlled by Al₂TiO₅ and MgSiO₃, respectively. The mass ratio of Ti₂O₃/ΣTiO₂ has a prominent influence on the total crystallization rate of anosovite crystals while the mass ratio of MgO/FeO has a slight influence on the total crystallization rate of anosovite crystals.