High-performance　hydrogel　electrolytes　with　eminent　toughness,　high　conductivity　and　anti-freezing　properties　have　extensive　applications　in　wearable　devices　or　implantable　sensors.　However,　it　is　still　difficult　to　integrate　excellent　mechanical　properties　and　high　conductivity　into　one　hydrogel　sample　simultaneously.　This　work　introduced　NaCl　into　a　poly(vinyl　alcohol)/poly(acrylic　amide)　(PVA/PAM)　double　network　hydrogel　to　prepare　PVA/PAM/NaCl　supramolecular　hydrogel　electrolytes　via　a　one-pot　method.　NaCl　introduces　physical　entanglement　into　the　PVA/PAM/NaCl　hydrogel　electrolytes　and　provides　a　dense　and　wrinkled　three　dimensional　(3D)　network　nanostructure.　The　PVA/PAM/NaCl　hydrogel　electrolytes　not　only　showed　excellent　mechanical　properties　(tensile　strength　up　to　477　kPa,　elongation　at　break　to　1072%　and　a　fracture　energy　of　2.484　MJ　m-3),　but　also　had　high　conductivity　(up　to　6.23　S　m-1).　A　strain　sensor　based　on　the　PVA/PAM/NaCl　hydrogel　electrolytes　exhibited　very　high　sensitivity　(gauge　factor　=　24.901)　with　the　ability　of　precise　and　reliable　detection　of　human　motions.　Hydrogels　also　showed　excellent　anti-freezing　properties　and　maintained　excellent　mechanical　properties　and　conductivity　at　-20　°C.　Introducing　a　physically　cross-linking　network　through　the　effects　of　a　metal　salt　could　promote　the　performance　of　the　hydrogels.　This　work　provides　a　new　insight　into　the　design　of　multifunctional　materials　with　applications　on　electronic　skin,　wearable　devices　and　biosensors.　This　journal　is　©　The　Royal　Society　of　Chemistry.