In order to ensure the flight safety of the aircraft, guarantee the bending fatigue durability of slat gear-rack mechanism in complicated working conditions, and Improve development efficiency, based on the analysis of aerodynamic loads, the virtual bending fatigue durability of slat gear-rack mechanism was analyzed used ANSYS and nCode. The effect of different surface roughness factors on bending fatigue life was analyzed. The results show that aerodynamic load is the main fatigue load during the working process of the slat gear-rack mechanism. The bending fatigue life of the slat gear-rack mechanism can be predicted under specific conditions. According to fatigue theory and virtual fatigue durability analysis, the integrated fatigue durability engineering method is applied to get the best design results, and the design cycle can be greatly shortened.