A self-healing piezo-ionic elastomer with dynamic hydrophobic-hydrolytic domains, named MESHPIE, was developed to achieve ultrafast self-healing and pressure sensing in both ambient and aquatic environments. Inspired by the self-healing and mechanosensitive ion channels in cephalopod suckers, MESHPIE combines hydrophobic C–F groups and hydrolytic boronate ester bonds in a polyurethane (PU) matrix. The hydrophobic C–F groups repel water molecules, while the hydrolytic boronate ester bonds enable self-healing through reversible hydrolysis and re-esterification. The material exhibits high self-healing efficiencies of 94.5% in air and 89.6% underwater, with self-healing speeds of 9.1 μm/min and 13.3 μm/min, respectively. Additionally, MESHPIE demonstrates remarkable pressure sensitivity of 18.1 kPa⁻¹, making it suitable for underwater robotics and human-machine interfaces. The integration of MESHPIE into an underwater toy submarine demonstrated its potential for signal transmission and LED modulation. The device also functions as a pressure-induced tactile sensor, modulating LED brightness in response to applied pressure. The self-healing properties of MESHPIE were validated through scratch tests, cut-and-spliced scenarios, and stress-strain analyses, showing efficient recovery of mechanical properties. The device's performance was further confirmed through electrochemical impedance spectroscopy (EIS) and capacitance measurements, demonstrating its ability to detect pressure changes and maintain functionality after damage. The combination of hydrophobic and hydrolytic groups in MESHPIE enables high self-healing efficiency and speed, with the C–F groups facilitating ion-pumping via ion-dipole interactions. The device's potential for practical applications in underwater sensing, soft electronics, and human-machine interfaces was demonstrated through various experiments, including LED intensity modulation and underwater object collision detection. The results highlight the effectiveness of MESHPIE in achieving autonomous self-healing and mechanosensitive performance in aquatic environments.A self-healing piezo-ionic elastomer with dynamic hydrophobic-hydrolytic domains, named MESHPIE, was developed to achieve ultrafast self-healing and pressure sensing in both ambient and aquatic environments. Inspired by the self-healing and mechanosensitive ion channels in cephalopod suckers, MESHPIE combines hydrophobic C–F groups and hydrolytic boronate ester bonds in a polyurethane (PU) matrix. The hydrophobic C–F groups repel water molecules, while the hydrolytic boronate ester bonds enable self-healing through reversible hydrolysis and re-esterification. The material exhibits high self-healing efficiencies of 94.5% in air and 89.6% underwater, with self-healing speeds of 9.1 μm/min and 13.3 μm/min, respectively. Additionally, MESHPIE demonstrates remarkable pressure sensitivity of 18.1 kPa⁻¹, making it suitable for underwater robotics and human-machine interfaces. The integration of MESHPIE into an underwater toy submarine demonstrated its potential for signal transmission and LED modulation. The device also functions as a pressure-induced tactile sensor, modulating LED brightness in response to applied pressure. The self-healing properties of MESHPIE were validated through scratch tests, cut-and-spliced scenarios, and stress-strain analyses, showing efficient recovery of mechanical properties. The device's performance was further confirmed through electrochemical impedance spectroscopy (EIS) and capacitance measurements, demonstrating its ability to detect pressure changes and maintain functionality after damage. The combination of hydrophobic and hydrolytic groups in MESHPIE enables high self-healing efficiency and speed, with the C–F groups facilitating ion-pumping via ion-dipole interactions. The device's potential for practical applications in underwater sensing, soft electronics, and human-machine interfaces was demonstrated through various experiments, including LED intensity modulation and underwater object collision detection. The results highlight the effectiveness of MESHPIE in achieving autonomous self-healing and mechanosensitive performance in aquatic environments.