In this work, a melt-spun amorphous Fe73.5Si13.5B9Cu1Nb3 alloy is subjected to high-pressure torsion (HPT) treatment under 6 GPa in order to enhance the alkaline hydrogen evolution reaction (HER) performance. Different HPT turns, including 1, 2, 5 and 10, are selected and the samples are marked as HPT-1N, HPT-2N, HPT-5N and HPT-10 N, respectively. The HPT treatment can lead to a significant structural change such as partial crystallization and defect generation on the Fe-based amorphous alloy with a considerable increase in the HER electrocatalytic activity. The HPT-5N sample shows the best catalytic performance, with an overpotential of only 174 mV at 10 mA cm−2 current density in 1 M KOH, which is 244 mV lower than that of the melt-spun alloy at the same condition. Moreover, it was established that the HPT-treated amorphous alloy shows good stability during the HER cycling process.