The FeTi brittle phase is a key factor affecting the performance of titanium alloy coatings. Reducing the FeTi brittle phase in the texture is one of the effective ways to prepare titanium alloy coatings with excellent performance. This work uses laser cladding technology to prepare Ti-6Al-4V coatings with excellent mechanical properties and corrosion resistance on the surface of mild steel. The relationship between the cladding process, microstructures, and performances of Ti-6Al-4V coating has been revealed. Low laser power and high powder feeding rate are beneficial for the formation of a more complete microstructure of Ti-6Al-4V coating, which can significantly reduce keyholes and microcracks at the FeTi interface zone. The shear strength of the 1000 W-1.5 r/min specimen is the highest (88.8 ± 7.1 MPa), and the high-angle grain boundaries (HAGBs) of Ti are used as the blocking site for cracks to prevent the propagation. The 1000 W-1.5 r/min specimen has a corrected Ecorr (−0.3145 V vs. Ag/AgCl) and smaller Icorr (0.3182 μA·cm−2), exhibiting excellent corrosion resistance. When the Ti-6Al-4V coating is intact, the TiO2 passivation film formed on the surface can effectively prevent the corrosion process from progressing. When there are through cracks caused by residual stress in the Ti-6Al-4V coating, the electrolyte solution can reach the FeTi interface zone through microcracks to corrode the Fe in the substrate, leading to coating failure. The research results provide valuable reference for the preparation of titanium alloy coatings with excellent performance on the surface of mild steel.