Abstract: The on-site operation environment of axial flow fan in metal mine is complex. The environ⁃ ment of high humidity，high dust and high air temperature in underground mine is superimposed on the oil fume exhaust generated by the operation of trackless equipment. During the high-speed and long-term oper⁃ ation of fan impeller，it is easy to cause the corrosion of impeller blades，which leads to the attenuation of fan performance and the shortening of service life，which affects the safety and efficiency of underground ventila⁃ tion in mine. In order to solve the above problems，the targeted transformation of this type of fan is carried out，and three core technical structure improvement schemes are put forward. First，the new steel-alumi⁃ num composite blade is adopted to realize the adjustable blade angle while prolonging the service life of the blade and optimize the operation performance of the fan. The second is to add an electric brake device at the end of the motor，which effectively solves the technical problem that the mine axial flow fan needs to stop in a short time. The third is to configure the impeller disassembly device to realize the safe and fast installation and maintenance of the fan impeller and blades. The practice shows that the three improvement schemes can effectively solve the problems of blade corrosion，low shutdown efficiency and inconvenient operation and maintenance in the actual operation of the fan. It is of great significance to ensure the stable operation of the fan，prolong the service cycle of the equipment and improve the operation and maintenance efficiency of the mine underground ventilation system. It can provide reference for the optimization and upgrading of ventila⁃ tors in similar metal mines.

Key words: axial flow fan in mine, new type blades, electric brake, impeller disassembly