Abstract: This paper focuses on the effect of end face roughness on the organization and mechanical properties of pulsed TIG welded joints of zirconium alloy clad tubes. It has been shown that the reduction in end face roughness significantly improves the weld surface quality and reduces water ripple defects, resulting in better weld shaping. Microstructure analysis shows that the weld zone organization is mainly composed of α+α′+β phases, and the heat affected zone is mainly α+β phase organization. The reduction of endface roughness helps to improve the uniform flow of liquid metal inside the molten pool, suppresses the abnormal growth of local grains, and improves the uniform consistency of the welded joint organization. The mechanical properties show that the reduction of endface roughness can optimize the welding thermal process, further improve the tensile strength and elongation after break of the welded joint, and the hardness value of the weld zone is more uniform. This study elucidates the influence of endface roughness on the quality of welded joints, and provides a scientific basis and practical guidance for the high-quality welding of zirconium alloy cladding tubes.