Skin defects resulting from various causes are common issues in clinical practice. The predominant approach to skin wound repair involves the application of wound dressings to facilitate healing. However, the current treatment methods face significant limitations, including insufficient functional restoration and inadequate blood supply. In this study, an injectable, self-healing composite hydrogel for skin wound repair is developed using a dynamic Schiff base reaction and hydrogen bonding. The hydrogel incorporates oxidized sodium hyaluronate (OHA), carboxymethyl chitosan (CMCS), and tannic acid (TA). Results indicate that the bio-functional hydrogel demonstrates excellent injectability, self-healing capability, and antibacterial properties. Subcutaneous implantation experiments in rats confirm the in vivo biocompatibility and biodegradability of the hydrogel. Both in vitro and in vivo findings suggest that the bio-functional hydrogel can expedite full-thickness skin wound healing in SD rats by promoting skin regeneration, suppressing inflammatory responses, increasing collagen deposition, and facilitating blood vessel formation. This research introduces a novel approach to the development of bio-functional hydrogels for full-thickness skin wound healing and regeneration.