Abstract: The present multiaxial fatigue model in high-cycle was assumed that the plastic deformation was linear to applied fatigue loading that was above fatigue limits, and the plastic strain energy could be calculated. The microscopic structure of material would be permanently change and produce equivalent macroscopic stress due to plastic energy. Given a distribution function of the stress, derive the crack nucleation life when the superposition of maximum equivalent macroscopic stress and applied loading stress achieves the material′s intrinsic fracture stress, consider in the changes of the above two stresses caused by microcrack, the fatigue life of continue to loading until the macroscopic crack appears could be worked out. The established multiaxial fatigue life prediction formula contains three material parameters, and through uniaxial fatigue experiment data to determine. Preliminary research indicated that the model had a satisfied prediction ability for the referenced multiaxial fatigue test data.