The internal combustion generator is widely used for power generation for its efficiency. The biogas generated from the gasifier is sent to the wet-dedusting and cooling facility for purification. Then we can get the clean biogas of which the quality can fully meet the requirement for the engines to work. The biogas is sent through the buffer tank into the engines connecting the generators directly. The power can be transferred to the power grid or the users directly. The exhaust gas discharged therefrom is about 500℃, which can be recycled to dry the feedstock or generate hot water or steam through the waste heat boiler.