The invention belongs to the technical field of pesticide residue removal and new photocatalysts, and particularly discloses a method of a self-template using alcohol acid dehydration microwave to in-situ prepare platy nanometer crystals inlaid with cubical hollow TiO2. The method comprises the steps that a precursor titanium oxide difluoride is added to polyhydric alcohol, carboxylic acid, acid anhydride or hydroxy acid where dehydration reactions can occur, the titanium oxide difluoride is used as a self-template, alcohol acid dehydration controllable hydration and microwave solvothermal are utilized to in-situ prepare the platy nanometer crystals inlaid with the cubical hollow TiO2. According to the method, not only are recyclable organic products synthesized, such as ether, alcohol ether and carboxylic acid ester, but also the platy nanometer crystals inlaid with the cubical hollow TiO2 with well-defined structures and excellent photocatalytic performance are prepared. The method achieves double benefits, is easy in post processing, low in cost, simple in technological operation, energy-saving and environment-friendly, can be applied to mass industry production, and has broad application prospects.