The work aims to better study effects of different substrate preheating temperature on as-prepared coating quality. Based upon heat conduction and energy equation, free surface of molten droplets was tracked in finite volume method (FVM) and fluid volume tracking method (VOF), and 3D geometry model in which droplets strike the substrate was built to simulate slice forming process. Effects of different substrate preheating temperature on the slice morphology and morphologic change process of internal droplets were analyzed. On this basis, the second droplet striking solidified slice was simulated to form the coatings. Law of influence of different substrate preheating temperature on coating morphology and residual stress was further analyzed. As substrate preheating temperature rose, temperature gradient between sediment and substrate decreased, which was conducive to the spreading of droplets. As spreading time advanced, gas was emitted more smoothly and porosity in slice decreased. The slice spreading thickness decreased gradually as temperature rose. Spreading radius increased gradually and morphology of the sediment was more close to discoid. Final coating morphology featured in thick edges and thin center as the substrate temperature rose. However, center density of coating increased constantly and void volume in the structure decreased gradually. Substrate preheating temperature shall fall in a certain range, then residual stress is likely to have an optimal value which guarantees better bonding strength between the coating and substrate.