The invention discloses a complex air mixing device for a subway air conditioner. The complex air mixing device comprises a shell and a
filter system, the shell is provided with a
fresh air port, an air return port and an air outlet, and the
filter system comprises a primary filter section, a secondary filter section, an
electret filter section and an electrostatic filter section. The primary filter section and the secondary filter section are arranged at the
fresh air port, the
electret filter section is arranged at the air return port, and the electrostatic filter section is arranged at the air outlet. A power supply module is arranged on the top wall of the shell, and a particulate matter concentration
detector is arranged in the shell, electrically connected with the power supply module and positioned between the
electret filter section and the electrostatic filter section. The complex air mixing device is capable of efficiently filtering
fine particulate matters in
fresh air and returned air and has bactericidal, sterilizing and
odor eliminating functions to truly guarantee
physical health of passengers in carriages. In addition, the complex air mixing device has a
synchronous detection function,
electric energy distribution and energy saving are realized, completeness of an air conditioner set can be guaranteed, and convenience in
assembly and utilization is achieved.