Objective： The Issatchenkia terricola WJL-G4 isolated from raspberry orchard was used as the experimental strain. In a medium using citric acid as the sole carbon source， the growth characteristics of the strain， the best conditions for citric acid degradation， and its tolerance were investigated. Method： The deacidification and growth rate were used as judgment indicators to screen the citric acid concentration， nitrogen source type and addition amount， and inorganic salt type and addition amount in the culture medium， and the single factor test was used to screen the temperature， liquid loading， inoculation amount， shaking table speed and culture time， and then orthogonal design experiments were further used to optimize the acid reducing conditions of the strains. Result： The results showed that the medium was screened. The best formula for reducing acidity was 10 g/L of citric acid mass concentration， the best nitrogen source was yeast extract， the addition amount was 5 g/L， the best inorganic salt was magnesium sulfate， and the best addition amount was 0.001 mol/L. When the temperature was 28 ℃， the liquid volume was 40 mL/ 250 mL conical flask， the inoculation amount was 1%， the rotating speed was 160 r/min and the time was 12 h， the deacidification rate was 91.82%， which was not only four times more efficient before optimization， but also reduced energy consumption and saved costs. In addition， the maximum mass concentration of tolerant SO2 of the strain was 8 mg/L， and the alcohol volume fraction tolerated was 5%. Conclusion： The Issatchenkia terricola WJL-G4 had the function of degrading citric acid， and its acid reduction efficiency was significantly improved under the optimal acid reduction conditions.