Fast healing of diabetic wounds remains a major clinical challenge. Herein, this study reports a strategy to combine nanofiber aerogels containing precision macrochannels and the LL-37-mimic peptide W379 for rapid diabetic wound healing. Nanofiber aerogels consisting of poly(glycolide-co-lactide) (PGLA 90:10)/gelatin and poly-p-dioxanone (PDO)/gelatin short electrospun fiber segments are prepared by partially anisotropic freeze-drying, cross-linking, and sacrificial templating with 3D printed meshes, exhibiting nanofibrous architecture and precision micro-/macrochannels. Like human cathelicidin LL-37, W379 peptide at a concentration of 3 µg mL−1 enhances the migration and proliferation of keratinocytes and dermal fibroblasts in a cell scratch assay and a proliferation assay. In vivo studies show that nanofiber aerogels with precision macrochannels can greatly promote cell penetration compared to aerogels without macrochannels. Relative to control and aerogels with and without macrochannels, adding W379 peptides to aerogels with precision macrochannels shows the best efficacy in healing diabetic wounds in mice in terms of cell infiltration, neovascularization, and re-epithelialization. The fast re-epithelization could be due to the upregulation of phospho-extracellular signal-regulated kinase (p38 mitogen-activated protein kinase) after treatment with W379. Together, the approach developed in this study could be promising for the treatment of diabetic wounds and other chronic wounds.