The invention provides sub-micron titanium dioxide as well as a preparation method thereof and a dye-sensitized solar battery containing the material, which belong to the technical field of solar batteries. According to the sub-micron titanium dioxide, the problems that the size of titanium dioxide prepared by a traditional method is difficult to control, the distribution of the size is non-uniform and the energy loss of the sunlight irradiation of a dye-sensitized solar battery prepared by the titanium dioxide is large can be solved. The preparation method of the sub-micron titanium dioxide, which is provided by the invention, comprises the step of preparing the colloid solution of titanium salt under an alkali environment and the step of generating the sub-micron titanium dioxide. The size of the sub-micron titanium dioxide prepared by the method provided by the invention is easy to control. The sub-micron titanium dioxide provided by the invention is prepared by the method. The dye-sensitized solar battery provided by the invention comprises a scattering layer prepared by the sub-micron titanium dioxide. According to the sub-micron titanium dioxide as well as the preparation method thereof and the dye-sensitized solar battery containing the material, the efficiency of the battery is obviously enhanced, and the loss of the energy of the sunlight irradiation is effectively avoided.