For decades, wound healing has been the focus of many researchers around the world, and their final objective is the development of effective approaches capable of accelerating the healing procedure. On the other hand, wound dressings with high flexibility, rapid hemostasis, good biocompatibility, and suitable porosity have received increasing attention. In general, skin trauma with uncontrolled bleeding is one of the main challenges in the management of clinical wounds. In the study, nanocomposite sponges of chitosan (CS)/polyvinyl alcohol (PVA)/carbon dots (CDs) were successfully fabricated by using the freeze-drying method. The physicochemical properties of the prepared nanocomposite sponges were analyzed through Fourier transform infrared spectroscopy, scanning electron microscopy, porosity, water absorption, water vapor transmission rate, and mechanical tests. The results show that the obtained CS/PVA/CDs nanocomposite sponges had high porosity, hydrophilicity, good water absorption capacity, and flexibility. In the following, in vitro cytotoxicity assays, hemolysis, and blood clotting exhibited favorable biocompatibility and nontoxicity. Besides, in vivo hemostatic potential tests on rat tail, liver, and leg injuries indicate that the sponge had high hemostatic efficiency. Taken together, the reported results indicate that the fabricated CS/PVA/CDs nanocomposite sponges could be used as wound dressings.