To address the urgent demand for high-reliability, high-elasticity flexible components in aerospace applications under extreme temperatures and complex load coupling, this study developed Ni₅₁Ti₄₇Nb₂ alloy wires using a vacuum melting-cold drawing-annealing synergistic control process. Further, high-elastic flexible hinges tailored for aerospace applications were successfully fabricated via mold-based thermal shaping. Experimental results demonstrate that alloy wires annealed at 400 ℃ for 10 min exhibit exceptional superelastic stress of 1616.5 MPa and a tensile superelastic strain of 6% across a wide temperature range from –120 ℃ to 120 ℃. Notably, the temperature dependence of superelastic stress (dσ/dT = 3.3 MPa/℃) is reduced by approximately 50% compared to traditional NiTi alloys. The flexible hinges, subjected to 70% tensile strain cyclic testing for 10 cycles at –120 ℃, retained a shape recovery rate of 96% without degradation in mechanical performance. These hinges have been successfully deployed in the elastic deployment mechanisms of deep space exploration probes, overcoming the limitations of conventional metallic materials under extreme temperature and complex load coupling conditions. This achievement marks a significant advancement in superelastic performance, offering an innovative solution for lightweight design and enhanced reliability in aerospace systems.