Methane power generating system is an energy saving and environmental friendly system. It’s to use industrial waste (organic waste in winery, food factory and etc.), agricultural waste (farm animal waste) or municipal domestic waste (restaurant waste, kitchen waste, urban waste and etc.) to produce biogas by anaerobic fermentation. Power generated by biogas engine may be connected to grid or self consumed. Waste heat from biogas engine may be used in production of biogas (anaerobic fermentation), greenhouse heating, industrial heat supply or civil heat supply. Besides, biogas may also be used as industrial fuel gas or civil fuel gas. Biogas liquid is used as liquid organic fertilizer. Biogas residue may be processed to solid organic fertilizer used in agriculture.