This study presents an injectable, ultrasound-powered, bone-adhesive nanocomposite hydrogel designed to accelerate the healing of irregular bone defects. The hydrogel is composed of amine-modified piezoelectric nanoparticles (KBTO) and a biopolymer hydrogel network, which exhibit enhanced bone adhesive strength and osteogenic capacity. The inorganic-organic interaction between the amino-modified KBTO nanoparticles and the bio-adhesive gelatin-chondroitin sulfate network increases the adhesive strength of the hydrogel by approximately 3-fold. Under ultrasound irradiation, the nanocomposite hydrogel generates a controllable electrical output (-41.16 to 61.82 mV), significantly enhancing osteogenic effects in vitro and in vivo. In vivo studies using a rat critical-size calvarial defect model validate the accelerated bone healing. Bioinformatics analysis reveals that the ultrasound-responsive nanocomposite hydrogel enhances osteogenic differentiation of bone mesenchymal stem cells by increasing calcium ion influx and up-regulating the PI3K/AKT and MEK/ERK signaling pathways. Overall, this work demonstrates a novel, wireless, ultrasound-powered bone-adhesive nanocomposite hydrogel that broadens the therapeutic horizons for irregular bone defects.This study presents an injectable, ultrasound-powered, bone-adhesive nanocomposite hydrogel designed to accelerate the healing of irregular bone defects. The hydrogel is composed of amine-modified piezoelectric nanoparticles (KBTO) and a biopolymer hydrogel network, which exhibit enhanced bone adhesive strength and osteogenic capacity. The inorganic-organic interaction between the amino-modified KBTO nanoparticles and the bio-adhesive gelatin-chondroitin sulfate network increases the adhesive strength of the hydrogel by approximately 3-fold. Under ultrasound irradiation, the nanocomposite hydrogel generates a controllable electrical output (-41.16 to 61.82 mV), significantly enhancing osteogenic effects in vitro and in vivo. In vivo studies using a rat critical-size calvarial defect model validate the accelerated bone healing. Bioinformatics analysis reveals that the ultrasound-responsive nanocomposite hydrogel enhances osteogenic differentiation of bone mesenchymal stem cells by increasing calcium ion influx and up-regulating the PI3K/AKT and MEK/ERK signaling pathways. Overall, this work demonstrates a novel, wireless, ultrasound-powered bone-adhesive nanocomposite hydrogel that broadens the therapeutic horizons for irregular bone defects.