Abstract: Lactococcus lactis LLY003 was an advantage of lactic acid bacteria isolated from the old Beijing acid bean juice, with a short growth cycle, efficient acid, adhesion of green bean starch to the ability to quickly settle.It could be used for industrial production of lactic acid bacteria drinks and mung bean starch flocculant.This experiment mainly evaluated the safety of the lactic acid bacteria and provided the security for the production and application.Through the animal experiments, harmful metabolite experiments, drug resistance experiments and other evaluation experiments determined the strains of bacteria as edible safety bacteria.The results showed that mice did not die during the animal experiments and all life activities were normal and the major organs were free of disease.The hazardous metabolites were negative.The common eight antibiotics were resistant to streptomycin, vancomycin and norfloxacin and were free of plasmids.Did not produce hemolysis and translocation.The results showed that Lactococcus lactis LLY003 was safe and laid the foundation for the production and application of new lactic acid bacteria.