Nonhealing diabetic wounds are predominantly attributed to the inhibition of angiogenesis, re‐epithelialization, and extracellular matrix synthesis caused by hypoxia. Although oxygen therapy has demonstrated efficacy in promoting healing, its therapeutic impact remains suboptimal due to unsustainable oxygenation. Here we propose an oxygen‐releasing hydrogel patch embedded with polyethylene glycol‐modified calcium peroxide microparticles, which sustainably releases oxygen for 7 days without requiring any supplementary conditions. The released oxygen effectively promotes cell migration and angiogenesis under hypoxic conditions as validated in vitro. The in vivo tests in diabetic mice models show that the sustainably released oxygen significantly facilitates the synthesis of extracellular matrix, induces angiogenesis, and decreases the expression of inflammatory cytokines, achieving a diabetic wound healing rate of 84.2% on day 7, outperforming the existing oxygen‐releasing approaches. Moreover, the proposed hydrogel patch is designed with porous, soft, antibacterial, biodegradable, and storage stability for 15 days. The proposed hydrogel patch is expected to be promising in clinics treating diabetic wounds.This article is protected by copyright. All rights reserved