Uncontrolled hemorrhage is a major problem both in surgical intervention and after trauma. Herein, we design an in situ constructable peptide network, mimicking and participating in the native coagulation process for enhanced hemostasis and wound healing. The network consists of two peptides including C6KL, mimicking platelets and C6KG, mimicking fibrin. The C6KL nanoparticles could bind to the collagen at the wound site and transform into C6KL nanofibers. The C6KG nanoparticles could bind to GPIIb/IIIa receptors on the surface of activated platelets and transform into C6KG nanofibers. The in situ formed peptide network could interwind platelets, fibrin and red blood cells, causing embolism at the wound site. In a lethal femoral artery, vein, and nerve cut model of rats, the amount of bleeding was reduced to 32.8% by C6KL and C6KG with chitosan/alginate. The biomimetic peptides show great clinical potential as trauma hemostatic agents.