Abstract: The influence of different zones of high-strength steel welded joint on the hydrogen diffusion and aggregation is different. The escaping behavior of the diffusion hydrogen in different zones of TIG welded 30CrMnSiNi2 steel joint after electrochemical hydrogen charging is studied by microscopic photographing. The size and distribution of the hydrogen bubble were observed. The tracing of diffusion hydrogen in the weld zone is studied by using hydrogen microprint technique. The distribution characteristic of the escaped diffusion hydrogen in high-strength steel welded joint is explored, which is completely opposite to that in low-carbon steel. The results show that the diffusion hydrogen in TIG welded 30CrMnSiNi2 steel joint mainly gathers in the weld zone and the heat affected zone. The grain boundary in the weld zone is the main location to hydrogen diffusion and aggregation, the stress inside the structure is the primary cause of hydrogen diffusion aggregation. The results give constructive suggestions for understanding the relationship between different structure and the diffusion hydrogen.