Full-thickness burn wounds in diabetes often present significant challenges in terms of timely progression of healing and even mortality. Multifunctional dressings that possess strong absorptivity and mechanical property while effectively regulating inflammation and promoting angiogenesis is therefore crucial. We have developed a novel sponge (CCGE) comprising carboxymethyl chitosan, gelatin, and glycerin for the purpose of promoting accelerated healing of scald wounds in diabetic rats. This sponge is loaded with epigallocatechin-3-gallate, which possesses antioxidant and anti-inflammatory properties. The incorporation of the crosslinker BDDE reinforces its mechanical characteristics by augmenting the interplay between the sponge structure through hydrogen bonding and covalent bonding. Moreover, the crosslinked sponges provide a highly absorptive layer, carboxymethyl chitosan show good biocompatibility and angiogenic effects, and the gelatin provide matrix metalloproteinases-9 targeting. The CCGE sponges exhibit high biocompatibility, facilitate fibroblast migration, and promote tube formation. The application of the CCGE sponges significantly accelerates wound healing of full-thickness scald wounds in diabetic rats, exhibits enhanced collagen synthesis, reduced levels of pro-inflammatory cytokines, and increased blood vessel formation within the wounded area. In summary, this study presents a multifunctional composite CCGE sponge dressing that effectively modulates ROS, inflammation, and angiogenesis to facilitate comprehensive burn wound tissue repair in diabetes.