With rapid development of food industry, the production of soybean sauce is increasing in recent years. The sauce wastewater is doing greater and greater harm to the water environment. In order to tackle this problem, the operation time on the sauce wastewater treatment were investigated. The results showed that the process has a better effect for ammonia nitrogen, the orthophosphate and COD removal. The effluent ammonia nitrogen was less than 5mg/L and the ammonia nitrogen removal efficiency could reach about 90% with the aeration time 2 h-3.5 h. The orthophosphate increased during the anoxic stage while decreased during the aerobic stage. At the end of the aerobic stage, the orthophosphate concentration and the COD could reach about 1mg/L and 21 mg/L respectively when aeration time was 2 h-3.5 h. The better operation time (the aeration time) was at 2 h-3.5 h and the system could get a good water quality for sauce wastewater treatment.