A dynamic hydrogel was prepared from N,O-carboxymethyl chitosan (NOCC) and oxidized aldehyde-containing hyaluronic acid (A-HA) by Schiff base reaction. The resulted NOCC/A-HA hydrogels were characterized by Fourier transform infrared spectroscopy and scanning electron microscopy (SEM). The rheological, swelling, and self-healing properties of hydrogels were determined. The hydrogels present interconnected porous structure, high swelling rate, and outstanding self-healing capacity. The biocompatibility of hydrogels was evidenced by MTT assay and zebrafish embryonic toxicity test. Human umbilical cord blood mononuclear cells (CB-MNC) were encapsulated in the hydrogel. High cell viability above 50% was obtained after 21 days culture. A mouse scald model was realized to evaluate the potential of cell laden hydrogel in wound healing. Compared to the control group and the hydrogel group, the cell laden hydrogel group exhibits faster epidermal regeneration, reduced inflammation and more neovascularization. Therefore, NOCC/A-HA hydrogels encapsulating CB-MNC could be a promising therapy in the treatment of burns or scalds.