This study firstly reports that low content of non-aggregated calcium hydroxide (Ca(OH)2) nano-spherulites (CNS) (200 ppm, diameters <5 nm) acting as cross-linkers pioneers highly stretchable self-healing PAA/CNS nanocomposite hydrogel (NC gel). Such NC gel exhibits increased mechanical properties (2300 % of tensile strain, 72 kPa of tensile strength, 0.611 MJ/m3 of toughness), excellent self-recovery (high recoverability against elongation of up to 1800% with tensile stress of 35 kPa), and most notably, remarkable self-healing ability (extensibility of 2100 % and toughness of 0.599 MJ/m3), suggesting even a small amount of CNS helps to establish a high stretchable and outstanding self-healing hydrogel.