A　new　functional　cellulose　aerogel　(Cell@PEI)　with　high　adsorption　efficiency　was　prepared　for　the　removal　of　diclofenac　sodium　(DCF)　by　ammonification　cross-linked　polyethyleneimine　(PEI)　with　the　surface　of　cellulose.　The　fabricated　Cell@PEI　adsorbent　was　characterized　using　field　emission　scanning　electron　microscopy　(FESEM),　X-ray　diffraction　(XRD),　Fourier　transform　infrared　spectroscopy　(FT-IR),　X-ray　photoelectron　spectroscopy　(XPS),　etc.　The　results　demonstrated　that　the　Cell@PEI　exhibited　a　distinct　three-dimensional　cell　structure　and　was　rich　in　functional　groups,　i.e.,　-OH,　C　=　O,　-NH2,　and　C　=　C.　The　Cell@PEI　presented　a　stable　crystal　structure　and　large　specific　surface　area　(241.41　m(2)center　dot　g(-1)),　which　was　approximately　42　times　as　much　as　bare　cellulose　aerogel　(5.82　m(2)center　dot　g(-1)).　In　addition,　a　series　of　adsorption　experiments　showed　that　the　adsorbent　had　good　adsorption　performance　for　DCF　with　a　maximum　adsorption　capacity　of　294.12　mg　center　dot　g(-1).　Furthermore,　the　adsorption　of　DCF　on　Cell@PEI　was　well　corresponded　with　the　Langmuir　isotherm　and　pseudo-second-order　adsorption　model.　Thermodynamic　study　proved　that　adsorption　was　a　spontaneous　exothermic　reaction.　Moreover,　the　introduction　of　PEI　into　Cell@PEI　aerogel　enhanced　the　electrostatic　interaction　and　hydrogen　bonding,　promoting　DCF　adsorption.　Importantly,　the　Cell@PEI　aerogel　could　be　reused　up　to　five　times　desorbed　by　NaOH　(0.5　mol/L).　Considering　the　above　results,　the　fabricated　aerogel　material　can　be　applied　to　remove　organic　pollutants.