Abstract: Liquid fertilizer sloshing can often occur within storage tanks of manure applicators during transportation or operation. It is very necessary to improve the smoothness and the quality of fertilization in the liquid manure applicator. This study aims to optimize the wave proof plate within the tank using advanced CFD (Computational Fluid Dynamics) simulation with the Finite Element method (FEM). A systematic investigation was also conducted to clarify the longitudinal impact of liquid fertilizer on the tank wall. The primary metric system was taken as the loading peak of the total longitudinal impact on the fertilizer storage tank. A specific evaluation was also carried out to determine the influence of various parameters on the performance of wave proof plate. These parameters included the lower edge height of wave proof plate, the position height and diameter of wave proof holes, the number of wave teeth on the wave proof plate, as well as the height of trapezoidal teeth. The optimal combination of parameters was determined for the anti-slosh baffle using Response Surface method (RSM) with CFD simulation. Specifically, the optimal combination of parameters was achieved, where the height of the lower edge was 345 mm, the position height and diameter of wave proof hole were 133 and 622 mm, respectively. In addition, two similar devices of fertilizer storage tanks were constructed to further validate the effectiveness of the optimized anti-slosh baffle. One tank was equipped with a commercially available wave proof plate structure, while another was fitted with the self-developed wave proof plate. The similarity ratio was used to derive the positions of impact load monitoring points on the heads of the similar tanks and the anti-slosh baffles. The sloshing suppression tests demonstrated that the fertilizer storage tank was reduced the sloshing amplitude of liquid fertilizer during braking. The superior performance was achieved to suppress the sloshing of liquid fertilizer, particularly for the better smoothness of the applicator and the high quality of fertilization. Notably, there was the less than 7% relative error between the CFD simulated and sensor-monitored peak values of the total longitudinal impact load. The accuracy of CFD simulation model was further validated for the similar criterion. Furthermore, a series of experiments were then conducted to investigate the impact of the baffle on the overall stability of the machine. The better performance was achieved to suppress the liquid fertilizer sloshing, particularly in the demonstration cases at the filling ratios of 0.5 and 0.8. The overall stability tests demonstrated that the fertilizer storage tank was significantly improved in the pitch angular speed and lateral angular speed, compared with a commercial tank. Specifically, the improvements were 20.0% and 17.0%, respectively, on field roads; while the improvements were 20.8% and 17.2%, respectively, on off-field roads. In conclusion, the CFD model and similarity criterion were verified to restrain the slosh of liquid fertilizer for the high stability and accuracy of fertilizer storage tank in the whole machine. This finding can also provide the valuable insights and strong reference to design the wave proof plates in the storage tanks for the liquid manure fertilizer applicators.