Ligilactobacillus salivarius has important commercial value.It is very important to realize high density fermentation and preparation for industrial application.In this experiment,L.salivarius AR809 was used as the target strain,and its high-density culture conditions were optimized by single factor experiment and response surface design.The optimum medium was formulated as follows(g/L):glucose 21.111 9,casein peptone 10,beef extract 10,yeast extract 7.047 5,diammonium hydrogen citrate 2.063 1,potassium phosphate dibasic 2,sodium acetate trihydrate 6.3,magnesium sulphate heptahydrate 0.58,manganese sulphate monohydrate 0.25,and tween 80 0.5 mL/L.In conclusion,this paper provides a data base for the next high-density culture of L.salivarius AR809.