Abstract: The fatigue tests were taken on the large angle welded joints of 10Ni5CrMoV steel with and without tangsten inert gas welding(TIG) dressing treatment on the toe.The fatigue life, the relation of load and stroke and the fatigue crack initiation at the same loading condition were analyzed comparatively.The welding residual stress was also measured.The stress field and the strain field of welded joints with and without TIG dressing treatment were calculated by the finite element method.The results indicate that the TIG dressing treatment can improve the fatigue property of the large angle welded joints of 10Ni5CrMoV steel.The fatigue life of the welded joints is increased 34% by TIG dressing on the toe at the same loading condition.The primary cause is that the TIG dressing treatment can improve the weld geometry and reduce the stress concentration on the weld toe.So the stress value in the toe is reduced at the same loading condition and the fatigue ability of the welded joints is increased.