The development of life-saving hemostatic materials for emergencies can reduce death caused by uncontrolled hemorrhaging. In this study, we developed a composite hemostatic material based on interactions between chitin and platelet-poor plasma (PPP) that promote in situ thrombin attachment to the chitin surface. Optimal conditions for preparing the chitin/PPP composite hemostatic material (CP), including reaction time, temperature, inducing ion, and thrombin concentration, were determined; thrombin activity and PPP clotting time were then measured under these conditions. We found that chitin and 2-fold-diluted PPP induced with 0.2 mol L⁻¹ CaCl₂ and reacted in a 35 °C water bath for 1 h yielded the fastest clotting time in vitro (75.0 ± 3.0 s). Furthermore, CP showed a more potent hemostatic effect than chitin in a rabbit model of arterial and hepatic bleeding, which was attributable to the strong adsorption of thrombin. The activated partial thromboplastin time revealed that CP promoted blood coagulation via activation of the endogenous coagulation pathway. CP caused no obvious cytotoxicity in L929 cells, and histopathological examination indicated that CP had no immunogenicity, and accelerated wound healing. These results highlight the potential for using CP as a hemostatic agent in clinical settings.