A preparation method for controllable growth of heterogeneous seed mesoporous monocrystalline rutile titanium dioxide. The method, by means of a wet chemical process in which titanium tetrachloride serves as a precursor, a silicon dioxide sphere containing a heterogeneous seed serves as a template, rutile titanium dioxide having a specific crystal plane exposed is grown hydrothermally, and mesoporous monocrystalline rutile titanium dioxide containing the heterogeneous seed is produced when the template is etched, implements the mesoporous monocrystalline rutile titanium dioxide having exposed the crystal plane of a heterogeneous seed epitaxial growth preparation (111), thus solving the problem of poor contact quality of an interface between a catalyst and a cocatalyst and low photocatalytic efficiency.