对４种低合金钢采用显微镜下录像测氢法研究焊接区扩散氢的逸出动态过程及其分布规律。结果表明，扩散氢在焊接区呈变形正弦曲线分布；在组织状态发生变化的结合部位存在氢的局部聚集。其聚集程度与焊接区的应力集中状况及显微组织的不均匀性有关。 Four kinds of low alloy steels were recorded under microscope for hydrogen evolution to study the dynamic process and distribution of diffusion hydrogen diffusion in the welding zone. The results show that the diffusible hydrogen is deformed sinusoidally in the weld zone, and local hydrogen accumulation occurs at the bonding site where the microstructure changes. The degree of aggregation is related to the stress concentration in the welding area and the non-uniformity of the microstructure.