In order to reveal the sloshing behavior of vehicle-mounted liquid hydrogen storage tanks and improve their transportation stability，a numerical simulation model of vehicle-mounted liquid hydrogen storage tank sloshing was established. The impact of liquid hydrogen fluid sloshing on the storage tank during braking and turning was studied. The effects of driving speed，longitudinal and lateral acceleration and filling rate on the sloshing behavior of liquid hydrogen in the storage tank were discussed，and a wave-proof plate was designed to suppress the sloshing of liquid hydrogen. The results show that the stable driving speed of the vehicle has little effect on the liquid hydrogen sloshing in the tank. The more urgent the vehicle brakes or turns，the more severe the liquid hydrogen sloshing in the tank，the more serious the impact on the tank，and the longer the time required for the liquid hydrogen to reach a stable state. The closer the filling rate is to 50%，the more severe the sloshing is. As the filling rate increases to 90%，the impact of liquid hydrogen on the storage tank is more significant. However，the higher filling rate reduces the liquid hydrogen movement space and makes the sloshing amplitude more gentle. The anti-wave plate in the tank can effectively separate the liquid hydrogen sloshing space，so that the maximum longitudinal impact force of the tank is reduced by 9.6% and 17.5%，and the maximum lateral impact force is reduced by 34.6%，which significantly reduces the impact on the tank and shortens the liquid hydrogen recovery time.