The invention relates to the field of methods for producing titanium dioxide powder, in particular to a method for preparing titanium dioxide powder by means of titanium dioxide acid hydrolysis by the aid of ultrasonic enhancement sulfuric acid processes. The method includes steps of a, carrying out acid hydrolysis on titanium raw materials to obtain titanium liquid, to be more specific, mixing the titanium raw materials and concentrated sulfuric acid with one another to obtain mixtures, then adding dilution water into the mixtures, starting ultrasonic waves to initiate main reaction, carrying out aging for 2-4 hours after the main reaction is completed, adding water into reaction products and leaching the reaction products to obtain the titanium liquid; b, carrying out sedimentation, crystallization, concentration and hydrolysis on the titanium liquid to obtain metatitanic acid; c, carrying out rinsing, salt treatment and calcination on the metatitanic acid to ultimately obtain the titanium dioxide powder. The method has the advantages that the acid hydrolysis efficiency can be effectively improved, accordingly, the yield of the titanium raw materials can be increased, and raw material consumption can be reduced; the yield of the titanium raw materials can be increased, the raw material consumption can be reduced, accordingly, high economic benefits can be created for enterprises for producing titanium dioxide by the aid of sulfuric acid processes, and the method has a broad application prospect and is particularly applicable to technologies for preparing the titanium dioxide powder by means of titanium dioxide acid hydrolysis by the aid of sulfuric acid processes.