Abstract: Part of the stop blocks in the caterpillar band of a vehicle were found to have cracks during the process of maintenance, and some stop blocks were also found to have cracks after assembling for a while but before service. In order to determine the failure mode and cause of the stop blocks, macro and micro observation, energy dispersive X-ray spectroscopy (EDS) analysis, microstructure examination, hardness testing, hydrogen content testing and comparison experiments were carried out. The results show that the cracking of the stop blocks is intergranular cracking due to hydrogen embrittlement. The hardness of the stop blocks material is close to the design upper limit and the material itself has higher brittleness, leading to a high hydrogen embrittlement sensitivity of the material. The cracking of the stop blocks was mainly caused by the higher hydrogen content of the surface layer, which was due to the ingress of hydrogen during the zincizing process. It has been proved that preventing the ingress of hydrogen during the zincizing process can effectively prevent the hydrogen-induced cracking of the stop blocks.