The production of alcohol from cassava as raw material has a relatively broad market in provinces such as Guangxi, Guangdong, Hubei, and Jiangsu in China. In the conventional production process, about 12-15 tons of wastewater are discharged for every 1 ton of cassava alcohol produced. The effluent temperature of cassava alcohol waste residue is high, containing a large amount of organic compounds and suspended solids, with COD reaching 30-60 g/L and suspended solids reaching 20-30 g/L. The pH is low, making it a typical high concentration organic wastewater. If the wastewater cannot be treated stably and reliably, it will inevitably cause serious pollution to the environment. In recent years, the government has attached increasing importance to the treatment of alcohol waste liquid that seriously pollutes the environment. The second level standard for COD allowed to be discharged from the alcohol industry waste liquid is ≤ 300 mg/L, and the first level standard is ≤ 100 mg/L. Based on the characteristics of cassava alcohol wastewater, an anaerobic aerobic combined process can be used to treat cassava alcohol wastewater, and the stable operation of the anaerobic process is crucial for the entire treatment system.