An anti-B7-H4 antibody, an antigen-binding fragment thereof and pharmaceutical use thereof. A chimeric antibody and a humanized antibody comprising a CDR region of the anti-B7-H4 antibody, a pharmaceutical composition comprising the anti-B7-H4 antibody and the antigen-binding fragment thereof, and use thereof as an anti-cancer medicament. A humanized anti-B7-H4 antibody and use thereof in the preparation of a medicament for treating diseases or conditions mediated by B7-H4.