Abstract: To investigate the influencing factors of the lateral sloshing modes of liquid in tank trucks, this study conducted numerical simulations using Fluent software based on the assumptions of theoretical modeling. For three typical tank truck tank geometries (cylindrical, elliptical cylindrical, and rectangular), the influencing factors of modal parameters such as natural frequency, damping coefficient, and force vibration mode of lateral sloshing were analyzed. Meanwhile, the feasibility of the numerical simulation results was evaluated through a non-full-scale tank truck experiment. The results show that the time function of the force exerted by liquid sloshing on the tank wall follows a sine-cosine variation law; the natural frequency of lateral sloshing is mainly determined by the liquid filling rate and tank geometry, while the liquid viscosity, external excitation intensity, and the number of anti-sloshing baffles have little effect on it; however, the liquid viscosity significantly affects the sloshing damping. In addition, the simulation results are in good agreement with the non-full-scale experimental results, fully verifying the rationality of the liquid model assumptions in theoretical modeling and the effectiveness of the Fluent numerical simulation method. The findings of this study provide important references for researching the liquid-solid coupling characteristics of tank trucks, analyzing the dynamic laws of lateral liquid sloshing in horizontal tanks, and constructing an equivalent mechanical model for lateral liquid sloshing.