Facile synthesis and achieving desired properties simultaneously in Eutectic gallium-indium liquid metal (LM) implanted hydrogels are still challenging. Herein, highly conductive, adhesive, anti-fatigue LM-doped hydrogels are prepared by employing the amphiphilic block copolymer (PS-b-PAA) stabilized LM nanoparticles as both conductive filler and co-initiator, which trigger the rapid gelation (<5 min) of 1-vinyl-3-carboxymethyl imidazole bromide (IL) and acrylic acid (AA) monomers via polymerization at room temperature in the presence of borax crosslinked polyvinyl alcohol (PVA) and sodium chloride (NaCl), to form PVA/P(IL-co-AA)/NaCl-LM hydrogels. The optimized hydrogel exhibits remarkable stretchability (702.84%), exceptional electrical conductivity (13.10 S m−1), robust interfacial adhesion strength (49.86 kPa), and a high fatigue threshold of 656.78 J m−2 (at 200% strain). Further, the hydrogels are used as wearable bioelectrodes to monitor tiny physiological signals, comparing favorably with commercial rigid electrodes. Moreover, the hydrogel-based triboelectric nanogenerator (TENG) with high open-circuit voltage (251.37 V) and outstanding fatigue resistance (15 000 cycles) can power common electronics. Besides, the TENG can also be used as self-powered sensors to construct a sliding click communicator for aphasia and amyotrophic lateral sclerosis patients. This work provides a unique strategy for developing LM-initiated self-catalytic hydrogels with advanced properties toward wearable sensors for clinical healthcare.