The invention discloses a method for preparing a spherical titanium-aluminum composite oxide carrier. The method is characterized by comprising the following steps: firstly, fully mixing titanium oxide powder with aluminum oxide powder, then adding the mixed powder to a soluble alginate water solution of which the mass concentration is 0.5-3.5% in batches; dropping the obtained titanium oxide-aluminum oxide-alginate suspension to the water solution of calcium nitrate to gelatinize after agitating and homogenizing, so as to form titanium oxide-aluminum oxide-calcium alginate composite pellets; soaking the composite pellets into a water solution containing acetic acid and chitosan to further coat and carrying out crosslinking; finally, washing, drying and roasting, wherein the total mass of the titanium oxide and aluminum oxide powder is 5-30% of mass of the soluble alginate water solution. The method disclosed by the invention is simple and feasible, mild in condition, low in energy consumption, and little in wastewater and exhaust gas emission, and the prepared spherical titanium-aluminum oxide carrier has the characteristics of being large in adjustment range of the ratio of titanium to aluminum, smooth in surface, high in strength and low in abrasion.