This article proposes a metal material impact fatigue life prediction model based on damage evolution laws. This model describes the damage evolution process of metal materials as a gradually increasing process over time, and by monitoring the changes in damage parameters, the lifespan of materials can be predicted. Meanwhile, considering the influence of the microstructure of metal materials on their fatigue performance, this paper also introduces the microscale characteristics of material parameters, further improving the accuracy and precision of the model. By comparing and verifying with relevant experimental results, it is shown that the combination of continuous damage mechanics and finite element analysis method can effectively evaluate the impact damage and subsequent fatigue life of metal structures.