High-quality seawater is the prerequisite for success of intensive marine aquaculture, and improving dissolved oxygen of aquaculture water is crucial for high-density aquaculture. Speece cone is one of the most efficient oxygenating equipments in aquaculture water. In view of the current situation of compact space of offshore breeding vessel, we optimized the selection of speece cone, and developed related accessories to achieve the purposes of efficient aeration and space saving. We applied fluid simulation technology to optimize the angle of speece cone, and reasonably used the jet and bias phenomenon caused by venturi structure to increase the dissolved oxygen effect. By the design and development of microporous aeration jet device with help of microbubble principle and secondary jet effect, we improved the efficiency of oxygen dissolved in water in the speece cone. According to the results of fluid simulation software, under the same other conditions, the speece cone section had the highest peak liquid velocity and the best dissolved oxygen at section angle of 28°. According to the comparative experimental results of whether there was an aeration jet device, the speece cone with aeration jet device was faster, and it is concluded that the accessory has good auxiliary function for operation of speece cone and has good value of application.