Components in severe environment often fail to work due to abrasion, corrosion and fractures, surface strengthening technology has important applications in the fields of aerospace, steel and metallurgy. Nickel-WC is an ideal coating material for improving both wear resistance and corrosion resistance of components surfaces. However, WC bottom–concentrated situation generally occurs owning to large density of WC particles (16.5 g/cm3), which can cause stress concentration and increase the risk of cracking. WC bottom–concentrated situation is not desired in the fabricated process. In this study, WC particles reinforced Nickel alloy layers were prepared with different preheating schedule on 42CrMo steel substrate by powder plasma arc welding technology. The work aims to demonstrate the microstructure evolution of hard particle reinforced Nickel based alloy surfacing layers at different preheating temperature (200 ℃ and 400 ℃) and investigate the effects on the mechanical and tribology properties.