The invention belongs to the technical field of preparation of fluorescent powder materials, and particularly relates to patent application matters of fluorescent powder capable of dimming luminescence color and a preparation method thereof. The fluorescent powder is prepared through doping and roasting rare earth ions, and a chemical formula of the fluorescent powder is CaSnO3:X%Eu<3+>. The preparation method comprises the following steps: weighing the preparation raw materials, and adding H2O2 into the preparation raw materials to obtain a mixture and uniformly mixing the mixture; adding ammonia water, and performing complete reaction; performing full roasting at 200 DEG C to 700 DEG C. The fluorescent powder provided by the invention has the advantages that the fluorescence control effect is more excellent, change adjustment of the color of light emitted by the fluorescent powder under ultraviolet excitation can be realized through regulation of different roasting temperatures, together with uniformity of the relevant preparation raw materials and convenience of a preparation process, a good foundation is laid for preparation, popularization and application of the fluorescent powder material with high quality, and therefore, the fluorescent powder has a better practical value and popularization and application values.