The physical and mechanical characteristics of saline soil are significantly influenced by salt content, with macro- and mesoscopic mechanical properties closely correlated. This study investigates the strength and deformation behaviors of saturated saline sand through indoor triaxial shear testing under varying confining pressures and salt contents. The key innovation lies in developing a coupled finite element and discrete element analysis model to simulate the mesoscopic behavior of saline sand under triaxial shear stress state. Flexible boundary conditions were applied, and appropriate contact models for salt-sand interactions were selected. By adjusting mesoscopic parameters, stress-strain curves and variations in porosity, coordination number, particle displacement, and contact force chains were analyzed. The study further explores shear band development and shear failure mechanisms by examining relative particle displacement and the breaking of contact force chains. Additionally, the influence of salt particle size on the overall strength of the DEM model was assessed. The findings provide valuable insights into the internal structural changes of saline sand during shear deformation, contributing to a better understanding of its mechanical behavior in engineering applications.