A numerical model of flow and heat transfer for micro-droplet deposition forming was established on 7075 aluminum alloy by adopting semi-implicit pressure-linked equation algorithm (SIMPLE), and the volume of fluid (VOF) method with Piecewise Linear Interface Construction (PLIC) was employed to reconstruct the free surface. The influence of process parameters including impacting velocity, relative distances between two successive molten droplets, the temperature of the substrate and droplet size on end-shapes morphology is simulated during fabricating 7075 aluminum alloy by micro-droplets, and the numerical models are validated with experimental results. The results show that the determination of reasonable impact velocity and droplet relative distances is the key to obtain a good precision and quality, and under the condition of 100μm diameter molten 7075 aluminum alloy droplet on a stainless steel surface at temperature 350K with velocity 1.5m/s, the distance between two successive droplets is 200μm, can obtain better forming effect. The simulation results agree well with the experimental results, better reflects the actual process of droplet impacting, spreading and solidification behavior, provides a reference for the practical application of the process.