The invention relates to a preparation method of lamellar stacking titanium dioxide nanoparticles. The preparation method comprises the steps of taking Ti3AlC2 as a material, corroding the Ti3AlC2 by adopting an acid solution, removing an Al atomic layer, and generating a two-dimensional material MXene, then taking the two-dimensional material MXene as a precursor, performing a hydrothermal reaction and an oxidizing reaction in sequence to obtain the lamellar stacking titanium dioxide nanoparticles. Compared with the prior art, the preparation method provided by the invention is simple in processing steps, the novel two-dimensional material is taken as a template, and the lamellar stacking titanium dioxide nanoparticles are synthesized by a two-step method of the hydrothermal reaction and the oxidizing reaction; the reaction condition is mild, the process stability is good, raw materials are easily obtained, the cost is low, and the preparation method of the lamellar stacking titanium dioxide nanoparticles is conducive to realizing the expanded production, and has a very good application prospect.