The enhanced fatigue resistance of superelastic Cu-Al-Mn shape memory wires were investigated via bamboo-like grain structure obtained by cyclic heat treatment (CHT). It was demonstrated that increasing the number of CHT cycles can promote the grain growth to a straight grain boundary, eliminating the triangular structure that generally caused brittle fracture. In particular, the 5CHT and 7CHT specimens displayed negligible residual strain subsequent to unloading, following exposure to cumulative strains ranging from 2% to 10%, thereby showcasing superior superelasticity. From the functional fatigue test, the fatigue life of the shape memory wire subjected to 5 CHT cycles exceeds 4650 cycles at 5 % strain, which is more than 5 times that of traditional polycrystalline quenched samples.