Abstract: To understand the characteristics of gas-liquid two-phase flow in the speece cone and improve its oxygenation performance, taking the speece cone in an oxygenation system of large-scale aquaculture vessel cabin as the subject, we carried out a two-dimensional transient numerical simulation of gas-liquid two-phase flow in the speece cone under different conditions (Gas inlet method, taper and aperture size) based on the Euler-Euler model, analyzed the gas volume fraction distribution, the internal flow field pressure and the velocity distribution, explored the flow law of gas-liquid two-phase in the speece cone, and determined the key structural parameters influencing the aeration and oxygen dissolving performance of the speece cone. According to the results, under a given air inlet flow, when the gas inlet was consistent with the water inlet from speece cone, the mixing degree of gas and water was high. The experimental verification shows that the speece cone with top inlet had the best dissolved oxygen performance compared with the other two methods. When the speece cone had the same volume, changes in the taper of the speece cone led to gas-liquid two-phase changes: a smaller taper, a higher speece cone, and longer motion path and mixing time of oxygen in the speece cone, favoring full oxygen dissolution. By the same gas inlet method, the gas-liquid two-phase distribution was similar in the speece cone. The volume fraction of the speece cone outlet gas increased with decreasing air inlet aperture, and when the air inlet aperture was reduced to d =10 mm, the gas and liquid were best mixed in the speece cone.