With the rapid development of the tunnels constructed under the rivers and seas in China, the research on face stability of shield tunnel in fault fracture zone with high hydraulic pressure has important theoretical value and engineering application significance. In this paper, considering the effect of interface between intact rock mass and fault fracture zone, the existing wedge-prism model is improved, and a new limit equilibrium prediction model considering geological interface is established. Based on the limit equilibrium theory, the expression of limit support pressure of shield tunnel surface is deduced, and the change laws of limit support pressure and failure inclination angle in the process of shield tunneling approaching the interface between intact rock mass and fault fracture zone are studied. The results show that when the shield tunnel face is far away from the interface face or has passed through the interface face, the failure range of the rock and soil mass in front of the tunnel excavation is consistent with that in the intact rock mass or fault fracture zone, and the result of the limit support pressure is consistent with the conventional existing wedge-prism model. When the shield tunnel is excavated to the distance of fault fracture zone interface is less than the critical failure length, as the distance decreases, the limit support pressure increases rapidly and the maximum is about 3.5 times than the value in intact rock mass. Therefore, the support pressure of tunnel face should be strictly controlled at this stage to avoid water gushing and mud sudden accident.