To investigate the atomization characteristics of the submerged top blow of the swirling spray lance, a corresponding spray lance model is established using hydrodynamic calculation methods, and the independence and accuracy of the model are verified. The calculation results show that during the atomization process of the swirling lance submerged injection, the penetration of the oil droplets first increases and then stabilizes over time. The oil droplets undergo secondary fragmentation near the gas–liquid interface, and the total Sauter mean diameter of the oil droplets rapidly decreases after approximately 0.004 s of injection, eventually stabilizing. Additionally, the larger the oil load, the larger the mean Sauter diameter of the captured oil droplets, leading to a higher total Sauter diameter. Furthermore, as the atomization temperature increases, the Sauter mean diameter of the captured oil droplets on the capture surface decreases. The results show that the rotary lance can effectively improve the atomization characteristics of submerged blowing, which is conducive to improving the melting quality, melting efficiency, and fuel utilization.