Airless tires consist of a hub, spokes, shear belt, and tread, with the shear belt being a crucial component of the tire structure. The structure and material parameters of the shear belt significantly affect the performance of the airless tire. Therefore, in the simulation of airless tires, accurately reflecting the material properties of the shear belt is particularly important, as it directly impacts the accuracy of the performance simulation. The reinforcement layer in the shear belt is a load-bearing material structure composed of rubber and steel cords. This paper focuses on simulating the radial stiffness of the ring-shaped tread formed by the shear belt and tread. The model particularly examines the varying tensile and compressive elastic moduli of the steel cord in the shear belt’s reinforcement layer. The results show that considering the different tensile and compressive elastic moduli of the steel cord can accurately reflect the stress state of the ring tire. If the classical elastic theory is used to simulate the tensile and compressive moduli of the steel cord for analysis, significant errors will arise, which would not meet the requirements of product design. This research provides important reference value for optimizing the design of airless tire structures using simulation methods.