Abstract: To improve the level of intelligence and automation in the optimization design of nailed slopes and to increase the efficiency of optimization design, an intelligent optimization design method for nailed slopes has been proposed, with an automatic safety factor calculation approach at its core. In this method, soil nail parameters are adopted as design variables, and an optimization model is formulated with the objective of minimizing the material cost of soil nails under the constraint of slope stability. The proposed method is then employed to solve the model. A case study is presented to demonstrate the application of the method in the optimization design of a nailed slope, along with recommendations for the selection of design parameters. The results indicate that the proposed optimization method is capable of reducing the soil nailing cost by 48.6% while ensuring safety. Furthermore, visualizations of the optimized soil nail arrangement and the critical slip surface are achieved. To balance convergence performance and computational efficiency, it is recommended that the initial population size be set to 200 individuals and the number of generations to 400. The findings of this study provide an effective approach for cost-oriented optimization design of nailed slopes.