Diabetic patients often exhibit delayed or incomplete progress in the healing of acute wounds, owing to poor blood perfusion. Platelet-rich plasma (PRP) has attracted much attention as a means to improve wound healing, because it contains high growth factor concentrations. However, the burst-like release of PRP growth factors results in a short half-life of these therapeutic proteins, thus greatly limiting the therapeutic effect. In this study, we prepared PRP from human umbilical cord blood and developed an in situ photocrosslinkable PRP hydrogel glue (HNPRP) by adding a photoresponsive hyaluronic acid (HA-NB) into PRP. The HNPRP hydrogel allowed for controlled release of platelet-derived growth factor-BB (PDGF-BB) and transforming growth factor-β (TGF-β) for up to 28 days. In vitro cell culture showed that HNPRP promoted migration of fibroblasts and keratinocytes as well as PRP and did not reveal the advantages of HNPRP. However, in a diabetic rat skin wound model, HNPRP treatment promoted faster wound closure. Furthermore, the HNPRP group, compared with the control, PRP and hydrogel only groups, showed significantly greater re-epithelialization and numbers of both newly formed and mature blood vessels. The HNPRP group also displayed higher collagen formation than did the control group. In conclusion, HNPRP enhances angiogenesis and skin regeneration and consequently achieves faster wound healing, thus extending its potential for clinical applications to treat diabetic skin wounds.