Abstract: The frequent occurrence of oil spills has caused great threat to environment and human health, so it is urgent to treat oily wastewater effectively. Current oil absorbing materials have limitations, such as low absorption capacity, high cost and environmental harm. Nanocellulose aerogel can absorb a large amount of oil because of its high porosity, high specific surface area and low density. After hydrophobic modification, nanocellulose aerogel has a significant advantage in oil-water separation. The preparation and hydrophobic modification of nanocellulose aerogel are reviewed in this paper. The structural characteristics of nanocellulose aerogel and their influence on absorption performance were introduced. The application of nanocellulose aerogel in adsorption of oil and organic solvent and separation of oil-water mixture in recent years were reviewed. Finally, the development status and future prospects of nanocellulose aerogel are presented.