The feasibility of preparing cellulose acetate/carbon black (CA/CB) composite nanofiber in one step through electrospinning process and investigating its potential oil absorbability and application for machine oil removal from aquatic environment was reported. Different CA/CB composite nanofibers were fabricated by electrospinning of cellulose acetate (CA) solution containing different loads of 0.7, 1.5, and 2.2% CB relative to the weight of CA and labeled as CA/CB0.7, CA/CB1.5, and CA/CB2.2. The scanning electron microscope (SEM) images showed continuous and smooth fiber with submicron diameter ranging from 400–900 nm with good adhering of CB into CA nanofiber. Furthermore, the CA/CB composite nanofibers exhibited high surface area compared with CA nanofiber, which reached 3.057, 2.8718 and 8.244 m2/g for CA/CB0.7, CA/CB1.5 and CA/CB2.2, respectively. Oil adsorption tests were performed with heavy and light machine oils. The CA/CB composite nanofibers showed higher affinity for oil removal from an aqueous solution than pure CA nanofiber. The CA/CB1.5 composite nanofiber has an exceptional performance for the adsorption of both oils, and the maximum oil adsorbed reached 10.6 and 18.3 g/g for light and heavy machine oils, respectively. The kinetic of machine oils adsorption was fitted well by the pseudo-second-order model. Besides, CA/CB composite nanofiber exposed good adsorption properties and respectable reusability after regeneration for four consecutive cycles. The results advocate the excellent potential of as-fabricated CA/CB composite nanofiber as a promising reusable oil adsorbent for oil spill cleanup applications.