Disclosed in the present invention is a new 11-oxo-7,11-dihydro-6h-benzo-[f]pyrido[1,2-d][1,4]azepine oxepin-10-carboxylic acid derivative serving as a hepatitis B virus surface antigen inhibitor. Specifically disclosed are a compound represented by formula (V) or a pharmaceutically acceptable salt thereof, and applications of the compound represented by formula (V) or the pharmaceutically acceptable salt thereof and a pharmaceutical composition thereof in the treatment of viral hepatitis B.
