The invention relates to a method for preparing a low-temperature titanium dioxide loaded photocatalysis coating layer, belonging to the technical field of photocatalysis coating layer preparation. The method is characterized in that photocatalysis mother liquor is prepared through preparing nanometer titanium dioxide dispersion liquid and polysiloxane. The method has the advantages of easy preparation technology, easy operation, good photocatalysis effect for adopting nanometer titanium dioxide to prepare, ability to coat and solidify under normal temperature, and to release high-temperatureagglomerating, ability to be used on the surface coating without high temperature resistant based material such as plastic, at the same time, the photocatalysis coating layer has good binding force of the selected polysiloxane ultraviolet with tolerance properties to metal, plastic, and glass, and simultaneously, good anti-aging property of the formed photocatalysis coating layer under the irradiation of ultraviolet.