Abstract: In order to propel efficient operation of biogas engineering in livestock and poultry farms and enhance their anaerobic digestion efficiency, three biogas projects were chosed and their anaerobic digestion technology, engineering operation management and input-output efficiency were analyzed. The results showed that continuous stirred tank reactor, upflow solid reactor and plug flow reactor were suitable for energy-ecological biogas engineering which had high suspended solids and high solid content in the fermentation material; elements matching the anaerobic digestion technology were the key point in daily regulation of biogas engineering; the maximization benefit of biogas engineering could be achieved by co-production the biogas heat energy, electricity energy and organic fertilizer with digested sludge and slurry；and the use of solar heating and the reuse of digested slurry into anaerobic digestion may save energy and reduce engineering operation costs.