Abstract: The tire inflation pressure is often inconsistent when the vehicle is equipped with the dual tire assembly (DTA). Under the influence of the inflation pressure difference, the hydroplaning behavior and characteristics of the DTA have not been revealed. Aiming at the problem, a new model considering the fluid-solid coupling of the accumulation water, the pavement surface, and the DTA with the inflation pressure difference was proposed. Its effectiveness was verified by experiment and simulation. Moreover, the influences of the inflation pressure difference on the hydroplaning behavior and characteristics were revealed. The results show that there is a lot of water in the gap between the dual tires, and its thickness far exceeds that of the water film when the hydroplaning happens. The water lifting force increases with the increase of the inflation pressure difference and the water film thickness. Moreover, the ABS control state is more prone to hydroplaning than the free-rolling state. This research can be used to guide the design and use of the DTA further to improve the driving safety of vehicles on wet pavement. At the same time, it also provides a reference for the teaching simulation and course experiment of the DTA hydroplaning dynamics.