A high-efficiency low-
noise axial flow fan mainly solves the technical problems that an existing axial flow fan is low in efficiency, high in 
noise and the like. According to the technical scheme, the high-efficiency low-
noise axial flow fan is characterized by comprising a main fan body (2), a radial annular inlet (outlet) air 
muffler device (1) and a muffling 
diffusion cylinder (4), wherein the two ends of the main fan body (2) are connected with the radial annular inlet (outlet) air 
muffler device (1) and the muffling 
diffusion cylinder (4) respectively. A cylindrical housing (209) of the main fan body (2) and a motor housing (215) form an 
airflow passage. The inner wall of the motor shell (215) is provided with an axial rib plate or a fan-shaped block to support a 
stator (205). The outer 
diameter of the motor housing (215) is consistent with the 
diameter of a hub of an 
impeller (216), the 
diameter of an inner cylinder of a front 
muffler and the diameter of an inner cylinder of a rear muffler. The two ends of the motor housing (215) are basically flush with one end of a main fan body housing. A 
flange fixing a rotator and an end cover are arranged on the inner side of the motor housing (215). Accordingly, resistance loss is reduced. An air inlet (outlet) flow passage is designed to be of a gradual-shrinkage structure and a gradual-expansion structure, so aerodynamic performance and efficiency are improved; by the adoption of the radial annular inlet (outlet) air muffler device and the main fan body housing muffling structure combining multiple mechanisms, the purpose of 
noise reduction is achieved. The high-efficiency low-noise axial flow fan can be widely applied to ventilation on various occasions such as mines, tunnels, industries and enterprises.