Provided are a B7H3 antibody-drug conjugate and medical use thereof. In particular, provided are a B7H3 antibody-cytotoxic drug conjugate or a pharmaceutically acceptable salt or solvate thereof, a pharmaceutical composition comprising the aforementioned conjugate or the pharmaceutically acceptable salt or solvate thereof, and use thereof in the preparation of a medicament for the treatment of a B7H3-mediated disease or condition, especially in the preparation of anticancer drugs.