A fan active noise self-lowering system includes a fan, a push assembly, at least one pickup unit and a digital signal processing unit. The pickup unit serves to capture the noise made by the fan to generate a noise input signal and transmit the noise input signal to the digital signal processing unit. The digital signal processing unit receives the noise input signal and processes the noise input signal to output a control signal for controlling the push winding assembly to operate so as to push the fan impeller of the fan to move up and down. Accordingly, the fan impeller will generate a reverse sonic wave to offset the noise.