The invention discloses a fluorescent functional monomer, a molecularly imprinted polymer, and a preparation method and an application thereof, which belong to the technical field of a high polymer material. The fluorescent functional monomer 9,10-di(1-vinyl-3-imidazolium chloride) methylanthracene is dissolved in anhydrous acetonitrile by 9,10-dichloromethyl anthracene and 1-vinyl imidazole, thematerial is heated, and is subjected to backflow. Compared with 9,10-dichloromethyl anthracene, the fluorescence intensity the fluorescent functional monomer is significantly enhanced, can be used asa fluorescent monomer, and contains a group capable of recognizing template molecule 2,4,6-trichlorophenol. Further, the modified ionic liquid is used as the fluorescent functional monomer, and polymerized with the template molecule and a crosslinking agent under the action of an initiator, and forms the molecularly imprinted polymer. The molecularly imprinted polymer realizes double recognition of the target molecule, has high selectivity and disturbing ability, and has great application value in detecting 2,4,6-trichlorophenol in the environmental water body.