采用宏观观察、化学成分分析、硬度测试、力学性能测试、金相检验、扫描电镜分析等方法对某氢气增压机活塞杆断裂原因进行研究。结果表明：活塞杆的断裂原因为原材料热处理工艺不当，导致活塞杆的力学性能降低；在高周循环应力作用下，活塞杆发生疲劳断裂。最后提出了相应的改进建议，以供相关人员参考。

Macroscopic observation, chemical composition analysis, hardness test, mechanical property test, metallographic examination and scanning electron microscope analysis were used to study the fracture reason of piston rod of a hydrogen booster compressor. The results show that the fracture reason of the piston rod was the improper heat treatment process of raw materials, which led to the decrease of the mechanical property of the piston rod, and the fatigue fracture occured under the action of high-cycle cyclic stress. Finally, the corresponding improvement suggestions were put forward for the reference of relevant personnel.