An electronic rectification-type alternating current cooling fan is composed of a PBT plastic cement outer frame, a brushless direct current motor and fan blades, wherein a non-isolated Buck circuit supplies power to the brushless direct current motor; the brushless direct current motor is fixed to the PBT plastic cement outer frame; the fan blades are fixed to a rotor of the brushless direct current motor; the non-isolated Buck circuit and an electronic commutator of the brushless direct current motor are located on the same circuit board; when alternating voltage of the frequency ranging from 47 Hz to 63 Hz and the voltage ranging from 85 V to 265 V is input, stable low voltage and direct current drive voltage is provided for the brushless direct current motor, the rotation speed of a fan keeps constant, and meanwhile the electronic commutator has the rotation speed frequency signal (FG) output function, the fan stalling alarm signal (RD) output function and the temperature controlling and speed adjusting (TPWM) functions.