Preparing a high-quality Co-based alloy cladded layer on the surface of magnesium alloy is challenging and uncommon. In this study, laser cladding technology was employed, and high-throughput experiment methods were utilized. The Co-based alloy cladded layer was successfully formed on the surface of AZ31B magnesium alloy under specific process parameters: P=2 000 W, v=300 mm/min, D=3 mm, S=+10 mm, and Q=20 L/min behind the molten pool. The resulting cladded layer exhibited excellent formability with no cracks, pores, or other defects. The focus of this study was to investigate the surface friction and wear properties of the Co-based alloy laser cladded layer and to understand the mechanisms behind its improvement. The results revealed that the Co-based alloy cladded layer demonstrated a stable running-in state during the friction and wear stage. It exhibited significantly lower maximum friction coefficient (0.571), average friction coefficient (0.268), and wear loss (2.3 mg) compared to the substrate. The strong metallurgical bond between the cladded layer and the substrate prevents large-scale peeling during friction. The cladded layer′s enhanced properties are attributed to the solid solution strengthening effects from the solid solution phase and ordered compounds, as well as the high-hardness carbides that contribute to layer strengthening. Additionally, the varying temperature gradients and solidification rates from the bottom to the top of the cladded layer result in grain refinement, significantly enhancing the microhardness. The average hardness of the cladding layer is approximately 10.8 times that of the magnesium alloy substrate. Overall, these impartments contributed to the remarkable enhancement in the friction and wear properties of Co-based alloy cladded layer.