Abstract: Chitosan-based conductive hydrogels have attracted extensive attention in electronic skins, human health monitoring, and flexible wearable sensors. In this work, MXene was dispersed in acrylic acid-chitosan solution, and then the acrylic acid monomer was in situ polymerized to synthesis the chitosan-poly(acrylic acid)-MXene hydrogels (CS-PAA-MXene). CS-PAA-MXene shows excellent mechanical properties. The tensile strength of the CS-PAA-MXene is as high as 0.6 MPa, and its elongation at break and toughness reach 1450% and 2.6 MJ·m⁻³, respectively. CS-PAA-MXene can adhere to various surfaces, including glass, plastic, rubber, copper and aluminum, etc. The maximum peeling force on the glass can reach 175 N·m⁻¹. After the cut CS-PAA-MXene contacts each other for 2.5 s, its resistance value returns to the pre-cut value, suggesting CS-PAA-MXene has excellent self-healing performance. CS-PAA-MXene strain sensors have been successfully used to detect a wide range of human movements, such as the joint flexions of finger, elbow and knee. Due to the cationic charge and antibacterial properties of chitosan, CS-PAA-MXene conductive hydrogels will have a good application prospect in self-adhesive and high-extensibility flexible sensors.