The Saccharomyces cerevisiae FM-S-115 strain has good function in degradation L-malic acid,in order to play a good role in degradation L-malic acid of FM-S-115 strain during wine fermentation,the main influence factors and mathematical relational model between deacidification ratio and main influence factors were analyzed using univariate analysis and Central Composite Design experiment. The results showed that fermentation temperature,inoculation amount and SO2 concentration were the main influence factors on the deacidification ratio of FM-S-115 strain,the optimum conditions were the fermentation temperature 26.26 ℃,the inoculation amount 5.15% and the SO2 concentraion 81.08 mg/L.The experimental values of deacidification ratio of FM-S-115 strain was 38.11%,which well matched with the response surface methodology predicted values.