Marine osteichthyes play an important role in the global carbon cycle, and their physiological activities have a significant impact on the oceanic carbon sink. This paper reviewed and summarized the progress of research on the impact of marine osteichthyes on the oceanic carbon sink, then analyzed the contribution of fishes to the oceanic carbon cycle through active and passive transport mechanisms, finally collated existing models on carbonate excretion. The research suggested that marine osteichthyes play an important role in the carbon storage of the deep ocean through processes such as respiration, vertical migration, and the sinking of dead organisms. These processes are not only closely related to the metabolic activities of the fishes but are also influenced by environmental factors such as water temperature, salinity, and pH levels. However, current quantitative estimates of the carbon sequestration by marine osteichthyes are limited, and there is a dearth of comprehensive research in this field. This paper emphasized the necessity for further in-depth research in the future, including the assessment of the global carbon fixation potential of fishes, the impact of environmental factors on the efficiency of fish carbon fixation, and the evaluation of the process of dead fish as a carbon sink. Additionally, the paper suggested the establishment of a global database for fish carbon fixation to facilitate international cooperation and enhance the scientific understanding of the role of fishes in the marine carbon cycle.