The floating wind turbine has high structure and low stiffness, and it is easy to produce rolling motion under the combined action of wind and waves, affecting their normal operation and structural safety. This study proposes a scientific approach to broadly suppress different modes resonate simultaneously in floating wind turbine structures using a multi-tuned liquid column damper (multi-TLCD) system. By simplifying the floating wind turbine structure through the concentrated mass method, we establish a mechanical model of the multi-degree-of-freedom motion system of the floating wind turbine-TLCD. Vibrational characteristic analysis of the floating wind turbine structure is conducted to identify natural frequencies and vibration modes. The resonance characteristics of various modes of the floating wind turbine structure under TLCD are studied to elucidate the suppression mechanism of the multi-TLCD on different modes resonate simultaneously. Results indicate that the TLCD’s position significantly affects the suppression effect on different resonance modes of the floating wind turbine. By properly arranging multi-TLCD, effective overall suppression of different modes resonate simultaneously in the floating wind turbine structure can be achieved.