Abstract: When the liquid inside the tank truck shakes violently, it will seriously affect the control operation of the vehicle and may cause damage to the tank body,and the wave deflector can effectively reduce the impact of the liquid. Based on an analysis of traditional wave deflector structure, this paper proposed a rotating wave deflector and conducted a bidirectional fluid-structure interaction analysis of liquid sloshing inside the tank under emergency braking conditions.By analyzing the impact of the liquid on different wave deflector types, the study obtained the gas-liquid phase distribution within the tank during braking, as well as the equivalent stress and displacement diagrams within 0.1 seconds. The simulation results showed that the new structure improved both load-bearing capacity and service life, thereby verifying the feasibility of the design and providing a new approach for wave deflector development.