The multiaxial high-cycle fatigue assessment method for welded joints was carried out. Von Mises equivalent stress method, Eurocode3 recommended method, IIW recommended method and Modified Whler Curve Method（MWCM）were used to evaluate multiaxial highcycle fatigue life of tubeplate welded joints, and results were compared with experimental fatigue life. Then the standard errors of estimated fatigue life for the four methods were analyzed. Results show that equivalent stress method can only be used to calculate multiaxial high cycle fatigue life under proportional multiaxial loads, whereas MWCM performed well to evaluate multiaxial fatigue life for welded structures subjected to both proportional and nonproportional multiaxial loads, which has a small standard error.