The invention discloses a pyrrolidine double-fluorine-boron strong fluorescent dye and a preparation method and application thereof, wherein the structure is as shown in formula (1), R1, R2 and R3 areH or C1-C6 linear or branched alkyl group, R5 is H, Cl, xylylene group, nonane group, benzene ring group, OR9, NR9R10, or SR9. R4, R6, R7 and R8 are each independently H, C1-C6 linear or branched alkyl, C1-C6 linear or branched cycloalkane group; wherein R9 and R10 are each independently H, CH2COOEt, oxo group, xylyl group, C1-C6 linear or branched alkyl or C1-6 linear or branched cycloalkane group; the pyrrolidine double-fluorine-boron strong fluorescent dye has the advantages of up to 998 GM double-photon absorption cross section at 700-900nm, high molar absorption coefficient, high fluorescence quantum yield, high light stability and double photon fluorescence and the like.