Anaerobic digestion has many excellent functions; it only benefits from energy recovery, but also reduces environmental impact by resource recycling and can be a component in preventing global warming and encouraging carbon recycling. Therefore, a two-phase anaerobic digestion method that divides anaerobic digestion into volatile fatty acids production and gas generation reaction was developed. In this system, pig manure is co-digested with rice straw in a dry anaerobic digestion system. Fluidized bed technology was originally developed for aerobic biochemical oxygen demand removal, nitrification and denitrification at the beginning of the 1970s, and was later introduced to anaerobic treatment processes as anaerobic fluidized bed. The up-flow anaerobic sludge blanket is a high efficiency anaerobic wastewater treatment process developed in the Netherlands in the 1970s. Anaerobic digestion is classified as either wet or dry anaerobic digestion by TS content in the digester.