A three-phase solidification model based on the volume-averaged method with considerations of non-equilibrium dynamic solute redistribution coefficient and constant solute redistribution coefficient is established. The morphologies of the temperature field and flow field are the same when compared to the simulation results of the two solidification models, as is the variation trend of solute field concentration. However, the dynamic solute redistribution coefficient solidification model predicts the solute distribution in the deposition layer with less error and is closer to the experimental data. In the laser cladding process, the solidification rate of the molten pool varies with the change in the solute redistribution coefficient, which leads to the instability of the solute distribution process and obvious element segregation. Our findings indicate that the dynamic solute redistribution coefficient has a significant impact on solute distribution in the deposition layer. To more accurately predict the solute distribution in the deposition layer, the change in the solute redistribution coefficient should be considered in the laser cladding process simulation.