In the paper,biomass gasification was taken as the basic conditions,and cooling heating and power loadof a building. Energy analysis of combined cooling heating and power(CCHP)system were done according to internal-combustion engine and exhaust and direct- fired Li Br refrigeration unit. And primary energy efficiency,primaryenergy saving,exergy efficiency and exergy cost were gotten. It can realize that cascade utilization of biomass energy bybiomass gasification CCHP system. Some references may be provided...