To determine the effect of ozonated water treatment on the microbial community structure of prepared aquatic products, high-throughput sequencing technology was used to investigate the effects of different ozonated water treatment methods (rinsing and soaking) and storage temperatures (4 and 10 ℃) on the bacterial community composition and diversity of grass carp fillets. The sensory score and total volatile basic nitrogen content in the ozonated water rinsing group 1 day after storage at room temperature were significantly higher than the ozonated water soaking and control groups. Compared with the control group, the ozonated water rinsing and soaking groups had decreased Shannon, ACE, and Chao1 indices, increased Simpson index, and significantly decreased Streptococcaceae and Aeromonadaceae relative abundance. The Shannon index of the ozonated water-treated grass carp fillets decreased when stored at 4 or 10 ℃ and the Simpson index increased compared with the control group. After storage at 4 ℃, Acinetobacter and Serratia abundances were significantly decreased, whereas Buttieuella and Lactococcus abundances were significantly increased in the ozonated water-treated grass carp fillets compared with the control group. At 10 ℃, Acinetobacter was significantly decreased, but Serratia and Pseudomonas abundances were significantly increased in the ozonated water-treated grass carp fillets (p<0.05). In conclusion, ozonated water treatment significantly altered the bacterial community structure and decreased the bacterial diversity of grass carp fillets. Post-treatment storage temperature also exerted a substantial effect on bacterial community structure.