The invention belongs to the technical field of method for characterizing activity of seed crystals, in particular to a method for characterizing activity of a titanium tetrachloride hydrolytic seed crystal, which is high in operability, fast, accurate, economic and applicable to solve the technical problems. The method for characterizing the activity of the titanium tetrachloride (TiCl4) hydrolytic seed crystal comprises the following steps of: adding the TiCl4 hydrolytic seed crystal into metatitanic acid size, uniformly stirring and filtering; calcining a filter cake to obtain titanium white, and measuring the content of rutile, wherein the content of the rutile is higher, the activity of the TiCl4 hydrolytic seed crystal is higher. By promoting the metatitanic acid to be converted into a rutile crystal form in the process of calcining the TiCl4 hydrolytic seed crystal, the content of rutile in the seed crystal is indirectly characterized so as to characterize the activity of the seed crystal. The method for characterizing the TiCl4 hydrolytic seed crystal is high in operability, fast, accurate, economic and applicable, has more obvious advantages than the conventional characterizing methods, and can be better used for guiding production.