<p>In order to quantify the effect of WC-reinforced particles on phase transformation and performance modification of laser cladding IN625 coatings, in this study, the mechanical performance and phase transformation of laser cladding IN625/WC composite coatings with different WC contents were comprehensively and quantitatively analyzed via characterization and CALPHAD, respectively. Results demonstrated that the grain characteristics (i.e., size and texture) and mechanical properties (i.e., microhardness and wear resistance) of the composite coatings were synergistically improved with the increase of WC content. XRD and EDS analysis showed that the coatings were comprised of <i>γ</i> phase, Laves phase, carbide particles, and <i>δ</i> phase. Additionally, the variations of <i>γ</i> phase, <i>δ</i> phase, <i>σ</i> phase, Laves, M₂₃C₆, M₁₂C, and M₆C with temperature and WC content were calculated through the secondary development of Thermo-Calc software. The research revealed that as WC content increased, the mole fraction of carbides in the coating increased, while the mole fraction of <i>δ</i> phase slightly decreased. The mole fraction of σ phase initially increased and then decreased, reaching a peak when the WC content was 8%. Higher carbide content resulted in increased hardness and wear resistance. The <i>γ</i>′, <i>γ</i>″, and <i>δ</i> phases generally enhance the strength and hardness of the coating, while the <i>σ</i> phase and Laves phase seriously impair its plasticity. According to performance requirements, the content of reinforcing particles can be adjusted to effectively control the precipitation of strengthening phase and detrimental phase between dendrites via CALPHAD.</p>