Fluorescent powder with reversible fluorescence transition as well as preparation method and application of fluorescent powder

The invention discloses a preparation method and application of fluorescent powder with reversible fluorescence transition. The preparation method comprises the following steps: heating asphaltene powder and an organic solvent at 40-300 DEG C for reaction, and cooling to room temperature to obtain a reaction solution A; pouring the reaction liquid A into a filtering device for reduced pressure suction filtration, and taking filtrate after filtration as reaction liquid B; and carrying out rotary evaporation drying on the reaction liquid B to obtain a target product fluorescent powder, namely the asphaltene wafer. The asphaltene wafer with the size range of 50-600nm is obtained by taking asphaltene as a raw material and using a single solvent one-step method, the asphaltene wafer presents orange fluorescence in a solid state (or a non-dispersed solution) and presents blue fluorescence in an organic solvent, and the conversion of the fluorescence color is reversible. The adopted raw materials are wide and easy t