This study presents the development of non-equiatomic CoCrFeNiCuNb eutectic high -entropy alloy achieved by adjusting the stacking fault energy. The evolved Co2Nb Laves phase and Cu -rich precipitates within the FCC matrix interacted with deformation twins, leading to fracture strength (1.8 GPa) and fracture strain (42%) with a steady-state strain -hardening.