Abstract: As an accurate method for predicting structural fatigue life under random loads,field intensity approach deserves foundation research.According to the basic theories of field intensity approach and the fatigue testing dates of smooth and notched specimens of the given turbine blade material,the equations of the strain field intensity and the damage field radii of the material were obtained by simulating the tests of notched specimens with finite element method.Then the dynamic thermo–elastic–plastic finite element analysis of the disc-blade structures was completed,and the strain field intensity of the dangerous part of the structures was calculated.Finally the fatigue life of the disc-blade structures was gained according to the strain-life curves of the blade material.The method is reasonable and the calculation process is clear,also the equations of the field intensity are simple.Thus they serve as good references to the fatigue life prediction of structures in complicated stress condition.