Abstract: The present invention provides a system for treating the blood of slaughtered animals, the system comprising: a storage tank for collecting and storing the blood of animals slaughtered in a slaughter plant; a blood treatment tank in which the animal blood is received and stored from the blood storage tank and into which a liquid microbial agent for treating blood is introduced so that microorganisms of the liquid microbial agent are allowed to react at a temperature of 25˜35° C. for 8-12 hours, thereby separating the animal blood into an amino acid solution and a waste blood sludge; a blood-treating agent supply unit for supplying the liquid microbial agent to the blood treatment tank; a water supply unit for supplying water to the blood treatment tank; a filtering means for filtering the amino acid solution discharged from the blood treatment tank to remove impurities; a heater for maintaining the blood treatment tank at a temperature of 25˜35° C.