This study presents a novel double network (DN) hydrogel adhesive with enhanced mechanical strength achieved through a balance between cohesion and adhesion. The hydrogel is composed of a rigid polyvinyl alcohol (PVA) network and a flexible sodium alginate (SA) network, with the PVA/SA ratio adjusted to optimize the balance between internal cohesion and surface adhesion. The hydrogel is further enhanced by incorporating polyphenolic tannic acid (TA) to improve adhesion and antibacterial properties. The DN structure allows for the formation of an interpenetrating network, which significantly enhances the mechanical properties of the hydrogel, including tensile and compressive strength, as well as fatigue resistance. The hydrogel exhibits a threefold increase in adhesive strength compared to non-balanced systems, with the highest strength achieved at a balanced PVA/SA ratio. The hydrogel also demonstrates excellent cytocompatibility, as shown by cell viability assays with HaCaT and NIH-3T3 cells, and strong antibacterial properties against Escherichia coli. The DN hydrogel's unique structure enables it to maintain its mechanical integrity under deformation, providing a favorable environment for wound healing. This study highlights the importance of balancing cohesion and adhesion in hydrogel adhesives to achieve optimal mechanical performance and functional properties for biomedical applications.This study presents a novel double network (DN) hydrogel adhesive with enhanced mechanical strength achieved through a balance between cohesion and adhesion. The hydrogel is composed of a rigid polyvinyl alcohol (PVA) network and a flexible sodium alginate (SA) network, with the PVA/SA ratio adjusted to optimize the balance between internal cohesion and surface adhesion. The hydrogel is further enhanced by incorporating polyphenolic tannic acid (TA) to improve adhesion and antibacterial properties. The DN structure allows for the formation of an interpenetrating network, which significantly enhances the mechanical properties of the hydrogel, including tensile and compressive strength, as well as fatigue resistance. The hydrogel exhibits a threefold increase in adhesive strength compared to non-balanced systems, with the highest strength achieved at a balanced PVA/SA ratio. The hydrogel also demonstrates excellent cytocompatibility, as shown by cell viability assays with HaCaT and NIH-3T3 cells, and strong antibacterial properties against Escherichia coli. The DN hydrogel's unique structure enables it to maintain its mechanical integrity under deformation, providing a favorable environment for wound healing. This study highlights the importance of balancing cohesion and adhesion in hydrogel adhesives to achieve optimal mechanical performance and functional properties for biomedical applications.