A chronic diabetic wound, one of the most severe complications of diabetes, has a high incidence and causes great pain to patients, threatening their lives. In this paper, oxidative konjac glucomannan (OKGM) was reacted with ε-poly-l-lysine (EPL) through the dynamic Schiff's base reaction to make a multi-functional hydrogel. This hydrogel had excellent mechanical properties, injectability, self-healing ability, adhesivity and cytocompatibility. The outstanding haemostatic property was also expressed in rat liver incision, liver injury and tail truncation models. In addition, this hydrogel exhibited unique antibacterial ability against the Gram-positive Staphylococcus aureus (S. aureus), the Gram-negative Escherichia coli (E. coli) and the Gram-negative Pseudomonas aeruginosa (P. aeruginosa). It also promoted wound healing, enhanced angiogenesis and regulated macrophage polarisation in the whole-layer rat diabetic wound model. The multi-functional hydrogel is a dressing with huge potential and prospects in chronic diabetic wound healing.