The work aims to prepare the reinforced composite film of polybutylene succinate (PBS) with graphene oxide (GO) as filler. First, GO was modified by dodecyl dimethyl ammonium bromide (DDAB), with the biodegradable material PBS as the matrix and GO as the nano-enhanced phase; and then, the PBS/GO composite films were prepared by the method of solution complex, and their mechanical properties, crystal melting behavior and thermal stability were characterized. The results of mechanical property test showed that, compared to pure PBS, 0.1% GO could increase the tensile strength and elongation at break of the composite film by 37% and 25% respectively. However, with the increase of GO, the tensile strength and elongation at break showed a downward trend. The thermal behavior analysis showed that the addition of GO increased the melting temperature and crystallization temperature of PBS and decreased the crystallinity. However, GO had no significant effect on the thermal stability of PBS. The addition of a proper amount of GO is helpful to improve the mechanical properties and crystallization and melting behaviors of the biodegradable materials of PBS.