Rover mobility is a critical factor for the successful navigation and operation of lunar exploration missions, especially on challenging terrains. Understanding the interaction between the rover wheels and the lunar surface is essential for optimizing the design to improve traction, reduce energy consumption, and ensure the rover’s stability. The aim of this study was therefore to develop a numerical model that reflects the characteristics of the Korea-Lunar-Simulant-1, and analyze the design variables of wheels that influence the rover mobility. To achieve these objectives, the characteristics of Korea-Lunar-Simulant-1 were measured, and the key-parameters influencing the characteristics were derived using the discrete element method with the Plackett–Burman design. A Box–Behnken design was used to analyze the impacts of the levels and combinations of key-parameters on the behavior characteristics, thus leading to the identification of the parameter levels and combinations that can simulate the behavior of the Korea-Lunar-Simulant-1. The derived combinations of the key-parameters were validated by comparison with the shear properties to verify the accuracy. Finally, based on the numerical model, the effects of wheel width and grouser spacing on mobility were analyzed. Consequently, the grouser spacing was found to be an interconnected optimization target with the wheel diameter and grouser height.