<p>This paper presents a numerical investigation into the effects of various parameters on the supercavitating flow field structure. Using the Delayed Detached Eddy Simulation (DES) method, the supercavitation flow was analyzed in detail, and the reliability of the numerical approach was verified through comparison with experimental results. The effects of cavitator rudder angle, cavitator diameter, aft-body shape, angle of attack, and tail fins on the supercavity morphology and flow field structure were explored under different simulation conditions. The study found that when the ventilation coefficient is less than 2.4, the cavity contour rapidly expands with increasing ventilation rate. Beyond this threshold, the rate of cavity expansion slows down. The cavitator rudder angle causes the cavity cross-section to become elliptical, affecting the shape and gas flow within the cavity. The presence of tail fins induces a localized pressure rise at the front of the fins, suppressing backflow and enlarging the gas leakage area, which in turn alters the supercavity’s ventilation characteristics. This leads to a reduction in internal cavity pressure and cavity size. Overall, the primary effect of tail fins on the supercavity is the suppression of internal backflow formation, which optimizes the gas leakage characteristics of the supercavitating vehicle.</p>