Lactobacillus plantarum Lp-S2 which has the ability to produce gamma-aminobutyric acid, was used as starting strain to develop Direct vat set(DVS). Then the centrifugation process and freeze-drying process were optimized. By orthogonal experiment the optimal conditions of centrifugation were identified as: centrifugal temperature 4 ℃, Time-consuming 30 minutes, centrifugal force 6 000 r/min. In this condition, the centrifugal recovery rate of Lactobacillus Lp-S2 is 83.8%. The cryoprotectant was optimized by single factor and orthogonal test. The best combination of cryoprotectants was 15% trehalose, 15% glucose and 10% skim milk powder. The survival rate of L. plantarum Lp-S2 Direct Vat Set reached 39.2%. The optimum pre-cooling time was 6 h. The number of viable cells of the direct-acting starter was 1.5×10¹² CFU/mL.