<p>Decellularized extracellular matrix-based bio-patches offer superior biocompatibility and bioactivity, making them an ideal implantation material for soft tissue defect repair. However, the fixation of these patches typically relies on sutures or staplers, causing secondary tissue damage, stress concentration, and excessive inflammatory cell infiltration. Here, we develop a novel self-adhesive small intestinal submucosa patch (A-SIS) fabricated by in situ polymerizing a biodegradable hydrogel adhesive layer on the surface of the SIS patch. The A-SIS demonstrated increased tensile strength, biodegradability, and strong wet adhesion to various soft tissues (including skin, heart, stomach, and intestine), with shear strength reaching 100 kPa and interfacial toughness of 700 J/m² for porcine skin. In vivo studies showed that A-SIS patches significantly reduced surgical manipulation time and promoted tissue integration with fewer inflammatory cell infiltrations compared to sutured SIS patches. Moreover, A-SIS patches effectively accelerated the healing of diabetic ulcers and full-thickness wounds in preclinical porcine models. This work not only reports a novel design and fabrication of decellularized extracellular matrix-based bio-patch with strong self-adhesive interface, but also offers a promising sutureless solution for clinical soft tissue defect repair.</p> Graphical Abstract <p></p>