Abstract: In order to assess the environmental and ecological effects of oyster culture in typical semi-enclosed bays, as well as to elucidate the role and significance of oysters in the management and restoration of marine environments. Based on high-throughput sequencing technology, we explored the characteristics of the changes in the structure and function of water body colonies in the oyster culture area within a typical urban semi-enclosed bay (Dapeng Cove) in four seasons, and compared the characteristics of the differences in environmental factors in the water body and sediment between the culture area and the control area in the four seasons. The results indicate that oyster culture caused relatively little disturbance to environmental factors such as nutrients in the water of Dapeng Cove, but its biological sedimentation enhanced the enrichment of total organic carbon (TOC), sulfides (Sul), and some heavy metals in the sea area. The high-throughput sequencing results show that the relative abundance of colonies such as Chloroflexi, Desulfobacteraceae and Actinobacteria in the winter oyster culture area was significantly higher than that in the control area (p<0.05). The redundancy analysis (RDA) reveals that the main environmental factors affecting bacterioplankton structure between the oyster culture area and the control area in winter were \mathrmSiO_3^2- , sea surface temperature (SST) and salinity. The results of biogeochemical function of water colonies predicted based on the FAPROTAX model show that the biogeochemical effects of nitrogen (N) and sulfur (S) mediated by bacteria in the oyster culture area in winter were significantly higher than those in the control area (p<0.05). In conclusion, oyster culture causes certain disturbances to the bacterial structure and composition of seawater in Dapeng Cove, but its degree and scope of influence are constrained by a combination of factors such as seasonal changes in physical and chemical factors and hydrological conditions. Furthermore, oysters culture facilitates the biogeochemical cycling of elements such as nitrogen and sulfur.