The invention relates to a method for producing titanium dioxide by using titanium liquid with low content of total titanium and a high iron-titanium ratio, which belongs to the field of production of titanium dioxide. To overcome a technical problem, the invention provides a novel production method for titanium dioxide, specifically a method of subjecting titanium liquid with low content of total titanium and a high iron-titanium ratio to hydrolysis to obtain titanium dioxide. The method comprises the following steps: step A, subjecting the titanium liquid, an external seed crystal, to hydrolysis to prepare metatitanic acid; and step B, treating metatitanic acid by using a conventional method so as to obtain titanium dioxide; wherein in the titanium liquid with low content of total titanium and a high iron-titanium ratio, the concentration of total titanium is 160 to 185 g/L (on the basis of the content of TiO2) and the iron-titanium ratio is 0.31 to 0.45, which is a key point of the hydrolysis process in the invention. With the method provided by the invention, the procedures of crystallization and filtration of ferrous sulphate are omitted, even the procedure of condensation of the titanium liquid is not needed, so considerable production cost is saved; the method is a production method for titanium dioxide through hydrolysis of the external seed crystal at normal pressure and has the advantages of small time consumption, a small amount of investment and low energy consumption; prepared titanium dioxide is anatase titanium dioxide and can be used for pigment-level titanium dioxide.