The invention provides a novel compound with antibacterial and antitumor activities, discloses a novel lactam compound and a preparation method and application thereof, in particular relates to a novel lactam compound prepared by microbial fermentation and application thereof, and belongs to the field of biotechnology. The chemical name of the lactam compound is (6S, 8aS, 9S, 11S, 12aR)-6-hydroxy-9,10-dimethyldecahydrobenzo[d]aza-decm-pentaene-2,4,12(3H)-triketone. The novel lactam compound has the advantages that experiments show that the compound has obvious inhibiting effect on the growthof fusarium oxysopoyum f.sp.cubence race 4 (FOC4), human hepatocarcinoma cell SMMC-7721 and mouse sarcoma cell s180, and has lower toxicity; therefore, the compound can be used as a raw material of anti-fungal pesticide or an anticancer medicament and has better application prospect; moreover, the preparation method for the compound is a biofermentation method, has simple steps and lower cost andis propitious to industrialized popularization and implementation.