Pt-based one-dimensional hollow nanostructures are promising catalysts in fuel cells with excellent activity. Herein, one-dimensional hollow FePt nanochains were shown to be efficient nanocatalysts in the hydrolysis of NaBH4. The characterization of composition, structure and morphology identifies an ultrathin shell (∼3 nm) with uniformly distributed Fe30Pt70 constituents. The H2 generation rate of hollow Fe30Pt70 nanochains achieves 16.9 l/(min · g) at room temperature, while the activation energy is as low as 17.6 kJ mol-1 based on the fitting over the whole reaction time span. After the catalysis of NaBH4 hydrolysis, the morphology and composition of hollow FePt nanochains remain unchanged. Furthermore, the structural stability of hollow FePt nanochains under Ga+ ion irradiation is clarified. Theoretical simulation indicates that the stopping range of such a Fe30Pt70 shell is 7.7 keV, which offers a prediction that structure evolves diversely under Ga+ ions below and above such energy. The Ga+ ion irradiation experiments show a consistent trend with the simulation, where Ga+ ions with kinetic energy of 30 keV make the hollow architecture subside and sputter away, while Ga+ ions with kinetic energy of 5 keV only etch the top and lead to an eggshell structure.