Abstract: 【Objective】 This project aims to optimize the experimental conditions for the treatment of potato starch wastewater by coupling of Acidophilic photosynthetic bacteria (PSB) and Bacillus atrophaeus (BA). 【Methods】 Potato starch wastewater was used as study materials and they were divided into treatment and control groups. The treatment groups were the compounding ratio, inoculation, culture methods of the two strains and the wastewater contaminants degradation (like COD and Malodorous gas) rates were used to reflect their effects. Finally, we tested the total application effect of the optimized experimental conditions for the treatment of potato starch wastewater. 【Results】 The optimized experimental conditions for the treatment of potato starch wastewater were∶ the ratio of PSB to BA =10∶1, 15% of inoculation, 30℃ of incubation, and incubated 144 h including light intensity 5,000 lx under anaerobic illumination for the first 72 h,then the next 72 h incubated under anaerobic illumination/aerobic =12 h∶12 h. The COD degradation rate under the optimized condition was increased from 16.9% in control group (without inoculation) to 98.21%, and it also showed more than 98% of degradation rate of other contaminates (like ammonia nitrogen, nitrate nitrogen, total phosphorus, mercaptan, hydrogen sulfide) and its self-flocculating rate was 8 cm/h. 【Conclusion】 The results suggested that the wastewater contaminated with high degradation rate by coupling of acidophilic photosynthetic bacteria and Bacillus atrophaeus is mainly attributed to the niche differentiation of the optimal growth pH.