The microstructure and fracture behavior of electron beam and laser beam welded stainless steel samples after charging hydrogen and tritium were studied by electron microscopy and the fracture strength was measured by tensile test. The results show that the fracture strength of the welding charged with tritium decreases a little, and the morphology of fracture surface has the typical hydrogen embrittlement mechanisms such as cleavage fracture, the second cracks and intergranular fracture. TEM observation indicates that there is a tendency to form cracks caused by the interaction between gas tritium and precipitates in grain boundary, and the microcracks initiate along deformation bands and grain boundary.