This study investigates the hydrodynamic performance of a novel wheel-track amphibious vehicle using a numerical model based on the Reynolds-Averaged Navier-Stokes (RANS) equations. The analysis highlights the vehicle’s resistance and sailing posture, revealing that as the Froude number rises, the original vehicle configuration experiences increased bow trim, submergence, and compromised stability and speed. To mitigate this, a bow shape optimization to a planar inclined structure is proposed. This optimization significantly reduces bow trim and resistance at medium and high speeds, resulting in a more smoother resistance curve. In addition, the impact of the locomotion mechanism on hydrodynamic performance was analyzed, showing that its optimization can further reduces resistance and increases speed. This study provides a theoretical basis for wheel-track amphibious vehicle design and guidance for future experimental validation and improvements.