The present invention discloses a mercaptonicotinic acid compound and preparation method and use thereof the structural formula of the compound is as shown in Formula I. Experiment demonstrates that the mercaptonicotinic acid compound inhibits in vitro botulinum toxin endopeptidase activity and Clostridium tetanus toxin endopeptidase activity, has a significant protective effect on botulinum toxin poisoning, and can be used for the prevention and/or treatment of botulism and prevention of botulinum toxin-exposure drugs and tetanus drugs.
