Abstract: The high temperature creep rupture test of T/P92 steel welded joints was carried out. The formation of creep damage of T/P92 steel was analyzed by means of metallographic examination, scanning electron microscopic analysis and quantitative analysis of creep holes. The results show that the merging of holes in the fine grain zone of T/P92 steel weld seam was not an instantaneous process, but a continuous growth of individual holes. At the same time, the spacing of holes decreased gradually, and the adjacent holes connected with each other and expanded into micro-cracks. Finally, creep damage occurred in T/P92 steel welded joints.