Abstract: To promote encapsulation effect and expand the application in the field of fresh-cut vegetable preservative,this study produced thymol-starch bacteriostat using starch nanoparticle as embedding material. The single factor trial determined thymol concentration,nano-starch emulsion concentration and stirring ratearemain factors that affect the encapsulation efficiency of thymol. The response surface methodology was used to optimize preparation parameters. The temperature,storage,and bacteriostatic stability of optimized bacteriostatic agent were tested by stability trial,and its effect on the microbial control of fresh-cut green pepper and cabbage were studied. The results showed that,when thymol concentration 0.87 mg/mL,nano-starch emulsion concentration 2.76%,stirring rate 450 r/min,the actual encapsulation efficiency was 90.40%±0.27%,which was close to the predictive value(90.58%). The encapsulation efficiency of the optimized thymol-starch bacteriostat was more than 65% at the end of 14 d storage at 4 and 37℃,and was more stability at 4℃. The embedded thymol showed longer bacteriostatic effect than free thymol against Staphylococcus aureus. The fresh-cut green pepper and cabbage that dipped in the thymol-starch bacteriostat and stored at 4℃,the quantity of total plate count,coliform group and S. aureus was lower than control group at 7^th d(P<0.05).