Exhaust mixer of turbofan engine

The invention relates to an exhaust mixer of a turbofan engine. According to the working principle of an injection pump and the characteristics that the temperature, the pressure and the flow speed of airflow in an inner duct are all higher than those of airflow in an outer duct, the airflow in the inner duct is used for being injected into the airflow in the outer duct, then the quantity and the energy of the airflow in the outer duct are increased, and the flow speed of airflow in the inner duct is lowered. According to the mixer, heat and kinetic energy taken away by exhaust of the engine can be utilized, the air flow and the energy can be increased when the internal energy of the engine reaches a certain level, the exhaust noise can be lowered, the pressure, the temperature and the speed are uniform after the airflow in the inner duct and the airflow in the outer duct are mixed, the quantity and the energy of the airflow in the outer duct can be increased, the fan efficiency can be improved, the propulsive efficiency can be improved, and the oil consumption can be lowered.