Abstract: A dual-network hydrogel was prepared by copolymerization and freeze-thaw cycles using acrylamide (AM), Sulfobetaine methacrylate (SBMA), and polyvinyl alcohol (PVA). The hydrogel was immersed in an inorganic salt solution (glycerol/water) containing Na₃Cit to form P(AM-co-SBMA)/PVA-Cit ionically conductive hydrogels. The composition and structure of the hydrogels were analyzed by scanning electron microscopy and Fourier transform infrared spectroscopy. The mechanical properties and adhesion performance were tested using a universal testing machine, and the strain-sensing capability was evaluated through simultaneous electrical resistance measurement during tensile stretching. It exhibits excellent mechanical properties, adhesion, water retention, and conductivity. The maximum elongation and ionic conductivity of this ionically conductive hydrogel are 940% and 1.83 S/m, respectively, with a tensile strength of 1.75 MPa and an adhesion strength of 27 kPa. As a flexible strain sensor, the hydrogel demonstrates excellent tensile strain sensitivity (GF = 3.021), rapid response, and stable electrical signal output.