This study analyzes cobalt (Co)-based amorphous claddings made of H13 die steel via the laser cladding technology. It also explores the evolution of the microstructure and properties of the Co-based amorphous coating at different laser powers, as well as its microstructure, hardness, and corrosion resistance. The results show that the upper and middle layers of the cobalt-based amorphous coatings are dominated by the amorphous phase, which is mixed with the crystalline phase. At the laser power of 467 W, the amorphous coating exhibited the most excellent performance. The main crystalline phases were FeNi3, γ-Co, and Cr2Ni3 phases. The upper layer of the amorphous coating had the largest content of 81.15%. The maximum hardness of the coating was 1192.5 HV0.2 in 3.5 wt.% NaCl solution, while its corrosion resistance was significantly improved.