Adsorbent materials as well as hydrophobic modification methods have been at the forefront of research creating environmentally hazardous waste. Herein, we report a facile, green preparation method for cellulose aerogels. Cold plasma technology was employed for hydrophobic modification of the aerogel surface using trimethyl-chlorosilane (TMCS) as the plasma. Notably, the modification procedure was considerably more rapid (less than 3 min), more efficient and economically viable than traditional methods. The highly flexible modified cellulose aerogels are hydrophobic (ca. 150°), oleophilic and ultralight (as low as 0.0196 g cm⁻³). Compared to conventional oil adsorbent materials, these low-cost, environment-friendly cellulose aerogels exhibit excellent adsorption properties (peanut oil, 34.5 g g⁻¹) as well as remarkable reusability (more than 15 times). Therefore, the preset work would play a significant role in further advancing the fields of adsorbent materials and hydrophobic modification methods.