The fermentation condition of Chinese yam ferment liquid was optimized with single factor experiments and orthogonal experiment. The Chinese yam ferment powder was prepared using spray drying. The changes in superoxide dismutase (SOD) activity between Chinese yam ferment liquid and recovery ferment liquid were analyzed. The abilities to remove superoxide anions and hydroxyl radicals were measured using the methods of pyrogallol autoxidation and H2O2/Fe system. the optimum fermentation process parameters of Chinese yam ferment liquid were as follow: sugar concentration 12%, inoculum concentration 6%, fermentation time 30 h, fermentation temperature 42 ℃. Under the control of this condition, the SOD activity of the Chinese yam ferment liquid was 15.35 U/mL. There was no significant change in the SOD activity between Chinese yam ferment liquid and powder after spray drying (P＞0.05). The results of antioxidant activity showed that the superoxide anion and hydroxyl radical could be effectively eliminated by the recovery ferment liquid.