The invention discloses a three-dimensional fluorescent 
covalent organic framework material as well as a preparation method and application thereof. A hexamethyl 
biphenyl aldehyde derivative and a series of pyrenylamine derivatives are used as raw materials, o-
dichlorobenzene and 
mesitylene are used as solvents, 
acetic acid is used as a catalyst, and 
solvothermal reaction is carried out for several days. After the reaction is finished, suction 
filtration and washing are sequentially carried out by using DMF and THF, carrying Soxhlet extraction is carried out for 24 hours, and 
vacuum drying iscarried out to obtain yellow 
powder, namely a target product. Hexamethyl 
biphenyl tetraaldehyde based on a steric effect and pyrenyl 
tetramine with fluorescent property are used as construction monomers, the synthesized Turn-on type three-dimensional fluorescent 
covalent organic framework has a rich cavity structure and a conjugated three-dimensional skeleton, the aggregation-induced 
quenching effect of fluorophores is avoided, the sensitivity of host-guest response of the material is improved, the material has a good application prospect in the field of 
fluorescence sensing, and the three-dimensional 
covalent organic framework is applied to the field of VOCs molecular decoding for the first time.