The efficient synthesis of trisubstituted trivalent phosphines remains challenging. Herein, we report a novel approach for rapid construction of these compounds from aldehydes under Lewis acid-mediated conditions. By using sterically hindered disubstituted phosphines, aldehydes can undergo a deoxygenative reaction to afford trivalent phosphorus compounds. This modular and practical method is characterized by operational simplicity, a broad substrate scope, and excellent functional group tolerance, which holds great potential for applications in organic synthesis.