TAT(47-57) is a cell-penetrating peptide. On this basis, fluorescein modification is added. Observation through optical microscope can better the physiological activity function of FITC-LC-TAT(47-57). For fluorescein-modified sequences such as FITC-LC-TAT (47-57), in peptide synthesis, it is necessary to add link arm amino acids, such as aminocaproic acid, PEG, etc., to increase structural rigidity.