The invention discloses an indoor fresh air volume instant adjusting technology based on indoor air qualities. A device for implementing the technology comprises an indoor-outdoor air ratio adjustor (1), an air inlet end (2), a primary filtering module (3), a fan module (4), a controller (5), a high efficiency filtering module (6), an adsorption module (7) for adsorbing activated carbon, kieselguhr and the like, an anion generator (8), a fresh air distribution box (9) and an air feed end (10). Outdoor air, indoor air or indoor-outdoor air mixture sequentially passes through the indoor-outdoor air ratio adjustor (1), the air inlet end (2), the primary filtering module (3), the fan module (4), the high efficiency filtering module (6), the adsorption module (7) for adsorbing the activated carbon, the kieselguhr and the like, the anion generator (8) and the fresh air distribution box (9) to be finally uniformly fed into a room through the air feed end (10). By means of the indoor fresh air volume instant adjusting technology based on the indoor air qualities, introduced fresh air volume can be real-timely adjusted in a sinusoidal waveform mode according to the difference between actual qualities of the indoor air and a preset value.