The present invention relates to a slightly acidic environment-sensitive and ketal-linked gefitinib-fluoroboronbipyrrole derivative and a preparation method therefor and a medical use thereof. The molecular structure of the derivative is as described in formula (I) of the description. In particular, the present invention relates to a gefitinib-fluoroboronbipyrrole derivative and a preparation method therefor and a pharmaceutical composition containing the compound, and the use thereof as a photosensitiser, especially the use in the treatment of cancers. In a normal tissue environment, due to the interplay between the gefitinib group and the fluoroboronbipyrroline derivative, the compound has a lower cytotoxicity. However, in the extracellular slightly-acidic environment of the tumour tissue, ketals hydrolyse and the fragments of the fluoroboronbipyrrole derivative obtained by hydrolysis exhibit an extremely high photosensitive activity, while a gefitinib derivative obtained by hydrolysis can be used as an inhibitor of epidermal growth factor receptor (EGFR) tyrosinase for inhibiting tumour growth. The compounds can be prepared into photodynamic therapeutic and chemotherapeutic double-efficacy anticancer drugs targeting both the tumour extracellular slightly-acidic environment and the EGFR tyrosine kinase.