This article synthesized and characterized a novel antibacterial hydrogel, which is formed using maleimide–thiol conjugation. Two precursors chitosan functionalized thiol groups and dextran functionalized maleimide groups prepared and characterized by Nuclear Magnetic Resonance (NMR). Key features of the hydrogel, such as gelation time, swelling behavior, viscoelastic properties, and degradation rate, were thoroughly examined. From gelation time result, we found that formed hydrogel gelation time could be changed with diffident weight percentage of precursors. Based on references, we found the best formular for the gelation and it was also determined for other studies. The swelling study indicated hydrogel has good flexibility and the degradation test indicated hydrogel is biodegradable. The viscoelastic test indicated hydrogel is an elastic solid. Given these attributes, this novel hydrogel has significant potential for use in various biomedical applications. Finally, colony-counting tests revealed that the hydrogel has an excellent antibacterial ability. Given these attributes, this novel hydrogel has significant potential for use in various biomedical applications.