<p>Soil penetration, a typical process of driving a penetrator into soil at a constant speed, is common in geotechnical engineering. In addition to this pure penetration movement, natural organisms also employ rotational motions in their burrowing strategies, which are believed to reduce penetration resistance and are beneficial for the design of self-burrowing robots. In this study, the three-dimensional discrete element method (DEM) was employed to investigate the effect of confining pressure on the reduction of rotation-induced penetration resistance. It is observed that the rotation-induced reduction in penetration resistance weakens progressively with increasing confining pressure. This study investigates the underlying mechanisms of rotational and confining pressure effects from a microscopic perspective by combining complex network analysis. The introduction of rotation not only markedly reduces the number of particles in contact with the penetrator but also reorients particle displacement toward the horizontal direction, providing greater space for the penetrator to advance. However, increasing confining pressure suppresses dilatancy, resulting in larger vertical components of particle displacement and a greater alignment of tangential contact forces beneath the cone along the vertical direction. The denser and more stable particle structure manifests in higher average degree and clustering coefficient. Moreover, a distinct linear relationship is identified between the weighted average degree and the stable value of penetration resistance, bridging microscopic network features with macroscopic response.</p>