The grounding pressure under the action of weight of the vehicle in water and the maximum grounding pressure under the supporting rolls were measured. 28 sensitive soil pressure transducers were evenly embedded in simulated soft seabed sediments 25cm below the crawlers. The results have shown that the measured values of grounding pressure are distributed in the form of hump curve. The maximum grounding pressure, 11.6kPa, occurred at about 3.7m point, which lay under 11 th supporting roller. The effects of backward displacement of center of vehicle gravity and nonlinear distribution of grounding specific pressure of vehicle crawlers on the traction force of the vehicle were theoretically calculated. Optimization of grounding specific pressure distribution by varying numbers of support rollers as well as pitch of track plates was carried out to enhance adhesion performance and trafficability of deep seabed vehicle on soft sediments.