Under high-pressure conditions, the microstructure of flexible pressure sensors tends to become saturated, potentially leading to structural collapse and irreversible damage, which consequently results in drastically reduced sensitivity, limited pressure range, and poor repeatability. Inspired by the structural features and efficient sensing mechanisms of cockroach antennae, this study develops a biomimetic composite dual-dielectric-layer iontronic pressure sensor. The sensor integrates a self-filled microstructured upper dielectric layer, simulating the sensory array structure, the wrinkled structure of the antennae and the dynamically tunable graded contact process of the antennae, with a fabric-based lower dielectric layer infused with ionic liquid, mimicking neural fiber networks. The synergistic effect of the dual-dielectric-layer structure endows the sensor with exceptional performance, including remarkable sensitivity (1569.9 kPa⁻¹), a comprehensive pressure detection range, an ultralow detection limit, fast response and recovery times, and remarkable durability. This study provides an innovative strategy the large-scale, low-cost fabrication of sensors, showcasing significant application prospects in medical monitoring, human–machine interaction, handwriting recognition, and information encryption.