The invention belongs to the fields of chemistry, materials and food safety, and relates to a molecular imprinting ratio fluorescent sensor, a preparation method and application thereof. The preparation method of the molecular imprinting ratio fluorescent sensor includes the steps that molecular imprinting is carried out through sol-gel polymerization, single-component dual-fluorescence emission cadmium telluride/8-hydroxyquinoline zinc nanoparticles provide fluorescence signals, holes after eluting bright blue are recognition sites, a mesoporous structure is formed after hexadecyl trimethyl ammonium bromide is eluted, and bright blue imprinted microspheres with the mesoporous structure are obtained, that is, the molecular imprinting ratio fluorescent sensor based on the single-component dual-fluorescence emission nanoparticles. According to the molecular imprinting ratio fluorescent sensor, preparation and application thereof, the obtained sensor prepared by the preparation method candetect bright blue with high selectivity and sensitivity, and provides color evolution and self-correction functions; and in addition, by effectively adjusting the emission wavelength of the sensor,the molecular imprinting ratio fluorescent sensor can be more widely used in detection of various colored substances.