A method of preparing an enhanced yellow-emitting carbon dots includes dissolving citric acid and urea in N,N-dimethylformamide, reacting at a temperature of 150-180° C. for 4-8 h to obtain a carbonized mixture, separating and purifying the carbonized mixture through column chromatography using an eluent prepared according to a volume ratio of dichloromethane to methanol from high to low, collecting a solution obtained by elution when the volume ratio of dichloromethane to methanol is 1:1-2, performing rotary evaporation to remove the solvent, and drying to obtain the yellow-emitting carbon dot. The yellow-emitting carbon dot with fluorescence intensity enhanced with the increase of temperature is synthesized. The yellow-emitting carbon dots has application value in the fields of temperature detection, biological imaging, photoelectric equipment and the like.