Abstract: High titanium slag is mainly used for producing titanium dioxide or titanium alloy. However its application in preparing the intermediate product, titanium sulfate, is seldom studied. In this paper, the sulfuric acid treatment of high titanium slag to prepare oxytitanium sulfate provided a new way for its resource utilization. Thermodynamic calculations showed that the one-step transformation of high titanium slag and concentrated sulfuric acid into oxytitanium sulfate was feasible, and the heating temperature should not be too high in order to avoid the cost and environmental pollution caused by the pyrolysis of concentrated sulfuric acid. Single-factor experiments showed that at a temperature of 350 ℃, a time of 150 min and a liquid-solids mass ratio of 3:1, the yield of titanium oxide sulfate could reach 95%; X-ray diffraction (XRD) and scanning electron microscopy spectroscopy (SEM-EDS) showed that the product, TiOSO₄, had a good crystal shape and was a multilayer lamellar stacked polymer.