The stability of tunnel faces in sandy ground is influenced not only by the mechanical properties of the ground but also by the groundwater conditions. Sand tank experiments prove that the morphological features of face collapse are influenced by the properties of ground and the groundwater conditions. Experimental simulations by mechanical-groundwater flow coupling analysis have been performed based on the finite difference method to verify that the analysis method is suitable. Parametric numerical analyses are also carried out to study the influence of the mechanical properties on the face stability of tunnels in the water-saturated sandy ground. The analysis results indicate that the face stability decreases considerably when the relative density of ground is less than 80 percent.