Abstract: High efficiency and uniformity often require the mixing of the liquid bait in the seedling stage of the sea cucumber aquaculture. In this study, an intelligent feeding of the liquid bait was proposed to enhance the consistency of the bait concentration and energy efficiency, with labor saving. The feeding machine was also integrated with the automatic bait delivery, stirring, and spraying into a compact system. The mixing mechanism was determined for the overall feeding performance and energy consumption. Three types of impellers were selected as the CBY paddles, the propeller, and the flow-through paddles. Computational fluid dynamics (CFD) simulations were performed to compare their mixing performance over a wide range of working conditions, including different rotation speeds (100-400 r/min), mixing times (0.5-2.5 s), and blade-to-wall distance (5-35 mm). Volume uniformity was used as the key performance indicator to evaluate the mixing effectiveness, while the stirring power was calculated using simulated torque values. A numerical analysis framework was established for the high accuracy of the simulation. Mesh independence was verified for the system stability at the grid counts of 700 000 for the CBY paddles, 720 000 for the propeller, and 900 000 for the flow-through paddles, respectively. The SIMPLE algorithm was selected for the pressure-velocity coupling, compared with the SIMPLEC, PISO, and Coupled ones. There was an optimal balance between computational efficiency and convergence stability. The mixture multiphase flow model was employed to characterize the non-Newtonian behavior of the sea cucumber bait, where the interfacial tension and viscosity were set at 0.072 N/m and 0.06 Pa·s, respectively. The superior adaptability and performance were achieved in the flow-through paddles among the tested impellers. Its mixing uniformity also exceeded the rest blades by 12% to 15% under various complex flows. Response surface method was utilized to determine the optimal operating parameters. An optimal combination of the parameters was achieved in a rotation speed of 290 r/min, a mixing time of 2.5 s, and a blade-wall gap of 20 mm. The mixture was achieved with the uniformity of 95.3%, while only 11.12 W of the power was consumed, indicating the highly efficient and low-consumption mixing. Additional experiments were conducted to further verify the performance, particularly with the inclusion of the baffles in the mixing tank. Results showed that the mixing uniformity increased to 96.8%, with only a slight rise in the power consumption to 13.1 W. The visualization of the flow confirmed that the field baffles effectively reduced the vortex formation for the minimal mixing dead zones. The baffles were validated to enhance the stirring environment without significantly increasing the energy requirements. A mesh independence test and sensitivity analysis were also performed on the turbulence models and numerical algorithms, in order to verify the reliability of the CFD simulation. The SIMPLE algorithm was chosen for its balance between computational efficiency and stability. Furthermore, the non-Newtonian behavior of the bait mixture was simulated using the Mixture multiphase flow model, thereby considering the interfacial tension and density variations between water and bait. A mechanical approach was also adopted with the simulation-driven optimization. Fluid dynamics modeling and experimental validation were integrated with the precise and consistent bait mixing. The manual workload was significantly reduced for the bait preparation and feeding. A scalable solution was also contributed to the automation and standardization of the sea cucumber farming, suitable for modern aquaculture. In addition to its application in aquaculture, the mixing structure and optimization can serve as a strong reference for the solid-liquid mixing in industries, such as food processing, chemical blending, and environmental treatment. The finding can provide a technical foundation for the intelligent control and energy saving of the fluid-based mixing equipment. Overall, a practical, efficient, and low-energy solution can also be offered for the liquid bait preparation and seedling delivery in smart aquaculture.