Scale effect exists in the model experiment, so large-scale model is generally utilized to reduce the scale effect. Based on Laxiwa arch dam, the hydroelastic model with a scale of 1∶100 is built, which is made of weighted rubber. The fluid-structure coupling system consisted of dam, foundation, water and fluctuatinon pressure is simulated overall. Some advanced testing equipment, technique and data processing software were used. Overall test and analysis of the modals and vibration response of dam and appurtenant structure under several working conditions were performed. The equivalent load is determined by inverse analysis method for flow induced vibration, then the dynamic response of the dam is obtained and influence of flow-induced vibration is assessed.