Abstract: In order to study disaster evolutionary process and failure characteristics of Yonglian tunnel of Ji'an-Lianhua highway under the effect of disturbance, taking F2 fault fracture zone as the research object, a large-scale 3D geologic model test system is developed. The system consists of model bench, geostress loading system, hydraulic loading system and information monitoring system. A new type of similar material of fault and surrounding rock used in the solid-fluid coupling model tests is developed through tests on a large number of different material ratios and physical and mechanical performance parameters. The test system and similar material are used to simulate the hazard of inrush of water and mud. The change rules of seepage pressure, stress-strain, displacement and flooder in the process of excavation for common and fault surrounding rock. The results of model test agree with the catastrophic characteristics of actual projects perfectly. The system is stable and reliable, and it can be widely used for model tests in other underground projects. The research methods and the results are of certain guiding significance to the practical engineering.