As a core component of deep-sea mining systems, the hydrodynamic resistance characteristics of seabed mining vehicle directly determine the economic efficiency of subsea mining operations. Current mining vehicle configurations predominantly adopt cuboidal geometries, exhibiting high turbulence intensity in wake vortices and substantial hydrodynamic resistance during motion. To address this limitation, this study investigates hydrodynamic resistance characteristics during motion and drag reduction methodologies for mining vehicle, proposing an optimization approach through semi-ellipsoidal shell-shaped buoyancy module design to refine overall vehicle morphology, thereby achieving significant hydrodynamic resistance mitigation. Utilizing an experimentally validated realizable k-epsilon turbulence model, analysing hydrodynamic resistance characteristics and flow field distributions with and without shell, examining the influence of head coefficientLE and rear coefficientLW on the mean drag coefficientCd. Key findings revealLW as the dominant parameter controllingCd. IncreasingLWreduces wake vortex dimensions and intensity while augmenting rear pressure, thereby decreasingCd. In contrast, global pressure at the shell head demonstrates negligible sensitivity toLE's variation, renderingLE's influence onCd statistically marginal. Under constant buoyancy material volume, minimal hydrodynamic resistance is achieved atLE=1.7 andLW=2.1, yielding a drag reduction ratio of 68.19%. These results can provide theoretical foundations for the design optimization of the shape structure of seabed mining vehicle.