AbstractHydrophobic ionogel has attracted much attention in underwater sensing as the artificial electronic skins and wearable sensors. However, when the low conductive ionogel‐based sensor works in the marine environment, the salty seawater weakens its sensing performance, which is difficult to recognize. Herein, a salt‐adaptively conductive ionogel with high submarine strain sensitivity is reported. Based on the preliminary improvement via the proton conduction mechanism, the conductivity of the ionogel further increases with the surrounding salinity rising up since the salt‐induced dissociation phenomenon, which is described as the environmental salt‐adaptive feature. In seawater, the conductivity of the ionogel is as high as 2.90 × 10⁻¹ S m⁻¹. Significantly, with its long‐term underwater stability and adhesion, the resultant ionogel‐based sensor features prominent strain sensing performance (gauge factor: 1.12) while combining with various soft actuators in the marine environment. The ionogel‐based sensor is capable of monitoring human breath frequency, human actions, and the locomotion of soft actuators, demonstrating its great potential in diving detection and intelligent preceptive soft robotics for marine environmental protection and exploration.