Hydrogel wound dressing is a new type of biomaterial with performance that is better than traditional and biological dressings. It has been extensively researched and the application in the field of biomedicine is common. In this study, we developed a simple and nontoxic method for preparing a new type of composite hydrogel, which formed through the Schiff-base reaction between the aldehyde of oxidized konjac glucomannan (OKGM) and the amino of carboxymethyl chitosan sulfate (CMSS). The chemical structures of this composite hydrogel were characterized by transform infrared spectroscopy (FT-IR). The micro-morphology of hydrogels were analyzed by scanning electron microscopy (SEM). Meanwhile, the properties of composite hydrogels including gelation time, swelling ability, water evaporation rate, hemolytic potential and biological compatibility were also investigated in different means. The results gained from these studies show that this composite hydrogels have a series of properties such as short gelation time, good swelling ability, appropriate water evaporation rate, excellent hemocompatibility and well biological compatibility. Considering these excellent performance, this composite hydrogels can be used as a wound dressing to treat injured skin.