This article reports the development of a novel switchable Pickering emulsion with rapid CO₂/N₂ responsiveness, which is stabilized using alumina nanoparticles hydrophobized in situ with a trace amount of a switchable superamphiphile via electrostatic interactions. With the introduction of CO₂ for 30 s, the Pickering emulsion can be spontaneously demulsified with complete phase separation; the emulsion can then be reconstructed in response to N₂ purging for 10 min followed by homogenization. Moreover, the stable Pickering emulsion can be stored for more than 60 days at room temperature without any visible change. The CO₂/N₂-responsive behavior of the switchable Pickering emulsion is attributed to the reversible desorption/adsorption of the switchable surfactants on the surfaces of the alumina nanoparticles upon the alternative bubbling of CO₂ or N₂. Thanks to the simple fabrication of the surfactant and the hydrophobization of the alumina nanoparticles, this research has developed an extremely facile and cost-efficient method for preparing a rapidly CO₂/N₂-responsive switchable Pickering emulsion. The dosage of the switchable surfactants has been significantly reduced by nearly 1500 times (from 150 to 0.1 mmol∙L⁻¹) as compared with the dosage used in previous studies. Moreover, the as-prepared CO₂/N₂-responsive switchable Pickering emulsion is environmentally friendly, mild, and nontoxic; thus, it holds great potential for practical applications with considerable economic and environmental benefits, such as oil transport, fossil fuel production, environmental gases detection, and the encapsulation and release of active ingredients.