For the serious vibration state of a large hydropower station sluice pier under the flood discharge condition, the systematic study of the pier prototype vibration test, the numerical prediction of the vibration response, and an operational safety evaluation are carried out. Firstly, the sluice pier prototype vibration test is executed, and the pier dynamic characteristics of the time and frequency domains are extracted under the frequent flood condition. Secondly, the whole hydro-dynamic load test model is set up based on the gravity similarity criterion, and the pier whole hydrodynamic load is tested and analyzed under abnormal flood and frequent flood conditions. The hydrodynamic load schedule lines obtained from this test are used as input to calculate the numerical flow-induced vibration of the pier. These results are compared with those of the prototype test. Then, the maximum vibration response of the pier is predicted under the abnormal flood condition. Lastly, the flow-induced vibration safety of the pier is evaluated. The results show that the large vibration amplitude can induce fatigue damage to the sluice pier, and is not conducive to normal staff operation. The suggestion for anti-vibration reinforcement of the pier is put forward.