A conjugate containing a fluorescent chromophore, which has any structure selected from C1 to C3. The conjugate containing the fluorescent chromophore provided by the described embodiments includes one fluorescent chromophore and two highly reactive groups R1 and R2 linked to the fluorescent chromophore by a covalent bond. The fluorescent chromophore in the conjugate initially has no or only weak fluorescence emission capability, and only after the two highly reactive groups react together with the corresponding molecule, the fluorescent chromophore has strong fluorescence emission. Therefore, the efficiency of conjugation of drug molecules to targeting molecules can be monitored in situ by the infrared fluorescence emission intensity and applied to the target-mediated drug delivery.