A TIGIT antibody, an antigen-binding fragment thereof, and a medical use thereof. The present invention relates to a murine antibody, a chimeric antibody, and a humanized antibody comprising a CDR region of the TIGIT antibody, and a pharmaceutical composition comprising the TIGIT antibody and the antigen-binding fragment thereof, and a use thereof as a medicament. In particular, the present invention also relates to a use of a humanized TIGIT antibody for preparing a medicament for the treatment of TIGIT-associated diseases or conditions.