Abstract: The microstructure and fatigue properties of 304 stainless steel at different annealing temperatures were tested and analyzed by means of MTS-Landmark testing machine, LEICA-LM/DM optical microscope and microhardness tester. The effects of different annealing temperatures on the fatigue damage evolution behavior of 304 stainless steel were studied. The results show that the grain size, elongation and fatigue life of 304 stainless steel increase with the increase of annealing temperature, while the yield strength, tensile strength, microhardness and elastic modulus decrease. The fatigue damage evolution law of 304 stainless steel at different annealing temperatures is similar, the damage factor increases slowly in the early damage stage, the damage accumulation is less and the plastic deformation is small; the damage factor increases rapidly in the late damage stage, the damage accumulation increases sharply and the plastic deformation is significant; and the damage factor rises rapidly above the critical value in the last few cycles until fracture. Based on the damage development equation,the fatigue damage evolution model of 304 stainless steel at different annealing temperatures is established, and the relationship between fatigue damage evolution behavior and fatigue properties of 304 stainless steel is quantitatively revealed,which provides a reference for annealing process optimization and microstructure control of the material.