Diabetic wounds are characterized by oxidative stress, chronic inflammation, and impaired tissue regeneration under persistent hyperglycemic conditions. Herein, we report an injectable dual-dynamic covalent hydrogel fabricated from phenylboronic-acid-functionalized oxidized sodium alginate and gallic-acid-conjugated chitosan. Crosslinked via reversible Schiff base and boronate ester bonds, the hydrogel exhibits excellent injectability, self-healing capability, and structural stability. Under hyperglycemic conditions, competitive glucose binding modulates the boronate ester equilibrium and induces glucose-responsive release of galloyl-containing species. These glucose-responsive release behaviors contribute to the antioxidant, antibacterial, and immunoregulatory activities of the hydrogel. In vitro and in vivo results demonstrate that the hydrogel promotes macrophage polarization toward the anti-inflammatory M2 phenotype, alleviates inflammatory responses, enhances angiogenesis, and accelerates skin regeneration. Collectively, the phenylboronic-acid-functionalized oxidized sodium alginate and gallic-acid-conjugated chitosan hydrogel represents a multifunctional glucose-responsive biomaterial with considerable potential for diabetic wound therapy.