Saccharomyces cerevisiae, Lactobacillus plantarum and Acetobacter pasteurianus HN 1.01 was mixed to ferment Vaccinium uliginosum L.. After determining the pH value, protein content, reducing sugar content, total phenols, flavonoids, procyanidins and anthocyanins content, antioxidant capacity including hydroxyl radical scavenging rate, and total antioxidant capacity to obtain the proportion of bacteria. The single factor test was conducted with pH value, protein content, reducing sugar content, total phenolic content, hydroxyl radical scavenging rate and total antioxidant capacity in order to determine the optimum range of fermentation time, inoculation volume, fermentation temperature and initial sugar content. The Box-Benhken center combination test was conducted based on the total phenolic content and hydroxyl radical scavenging rate to optimize the fermentation process. The results showed that under the conditions of fermentation time of 62h, inoculation volume of 6%, fermentation temperature of 38.5℃, and initial sugar content of 15.5°Bx, the total phenolic content reached (53.27±0.16)mg/100mL and hydroxyl radical scavenging rate reached (83.88±0.19)% in ten-fold diluted Vaccinium uliginosum L. fermentation liquid, which respectively increased by 56.91% and 34.34% after optimized. The hydroxyl radical scavenging rate was significantly higher than that of the positive control group (p<0.01) and it was about 5 folds higher than that of the 2mg/mL vitamine C solution. The test was expected to provide guidance for the deep processing of Vaccinium uliginosum L..