Clinical use of intraoperative auto-transfusion requires the removal of platelets and plasma proteins due to the pump-based suction and water-soluble anticoagulant administration, which causes dilutional coagulopathy. Herein, we develop a carboxylated and sulfonated heparin-mimetic polymer-modified sponge that could spontaneously adsorb blood (1.149 kg/m-2 s-1/2) along with instantaneous anticoagulation. We demonstrate that intrinsic coagulation factors (especially XI) are inactivated by adsorption to the sponge surface, while inactivation of thrombin in the sponge-treated plasma effectively inhibits the common coagulation pathway. Benefiting from the multiple inhibitory effects of sponge on coagulation enzymes and calcium depletion, the whole blood auto-transfusion in trauma-induced hemorrhage is unprecedentedly realized. The transfusion of collected blood favors faster recovery of hemostasis compared to traditional heparinized blood in an animal model. Our work not only develops a safe and convenient approach for whole blood auto-transfusion, but also provides the mechanism of action of self-anticoagulant heparin-mimetic polymer-modified surfaces.