In this work, the powder injection process at the bottom of the converter was numerically simulated by establishing a coupled gas-liquid-solid mathematical model. The effects of powder injection speed, solidgas ratio, particle size, and injection position on the trajectory and residence time of particles in the molten pool are studied. The discrete phase and continuous phase coupling solution method is used to analyze the change of the molten pool flow field after powder injection. It is found that increasing the spraying rate can reduce the particle concentration near the liquid surface from 2.3 kg/m 3 to 1.18 kg/m 3 . Increasing the solid-gas ratio from 10 kg/m 3 to 30 kg/m 3 can increase the powder distribution ratio from 70.9% to 93.1%. The larger the size of the particles, the easier it is to stay near the liquid level, and the maximum can reach 2.13 kg/m 3 . Finally, it was also found that spraying powder at 0.7 R can make the powder more uniformly distributed in the molten pool.