Abstract：Hydrogel can significantly expand in water and maintain their original structures and properties. Hydrogels have a promising application in enrichment and separation of low concentration heavy metal ions, because of the large adsorption capacity, fast adsorption speed, easy analysis, rich source and being environmentally friendly. However, the traditional hydrogel adsorbents prepared from chitosan, cellulose and other natural polysaccharides have poor mechanical properties, so it is necessary to synthesize a hydrogel adsorbent having good mechanical properties, which restricte their application in heavy metal adsorption. In this work, cellulose-chitosan / polyacrylamide (Ce-Cs/PAAM) double network hydrogel was prepared by a one-pot method. 0.5 g of banana fiber cellulose and 0.5 g of chitosan were dispersed in 20 mL of 0.1 mol/L acetic acid (the precursor solution for the first network ) and stirred at 60 ℃ for 5 h. The chitosan could be dissolved quickly while the banana fiber cellulose was partially dissolved. Then 4.26 g of acrylamide (the precursor solution for the second network) and 3 mL of epichlorohydrin (crosslinking agent) were added into the solution by magnetic stirring at 25 ℃ for 1 h. After that, 0.02 g of N, N-methylene diacrylamide (crosslinking agent), 0.02 g of potassium persulfate (initiator), and 0.2 g of α - ketoglutaric acid (light initiator) were added to the mixed solution and stirred for 15 min.The first and second network were polymerized and crosslinked simultaneously. The obtained solution was placed at 25 ℃ for 24 hours. The two polymer networks generated upon UV-curing for 6 hours to further polymerized the second layer of networked (polyacrylamide) under the action of light initiator, followed by washing in deionized water twice a day for 7 days to produce a white opaque gel. Cellulose-chitosan (CeCs) and polyacrylamide (PAAM) hydrogel were prepared as control. The structure of the three types of hydrogels were characterized by Fourier transform infrared spectroscopy (FTIR), scanning electron microscope (SEM) and X-Ray Diffractometer (XRD). The changes of functional group composition, surface structure, crystallization degree, mechanical properties, swelling properties and adsorption properties of samples were investigated. The results showed that the Ce-Cs / PAAM hydrogel was a three-dimensional porous and double network structure with excellent mechanical strength and toughness. Under the compressive strain of 90%, the maximum compressive stress was reached to 60 MPa. The swelling ratio in water was 9.56 mg / mg, and the swelling ratio in alkaline solution (pH 12) reached to 15.34 mg / mg. The maximum adsorption capacity of Cu2+ ions on Ce-Cs/ PAAM hydrogel was 312.4 mg/g (Qe) under the concentration of C0 at 350 mg/L, pH at 5.5 and adsorption time for 90 min. Compared with polyacrylic acid / humus double network hydrogel (151.00 mg/g), the adsorption capacity of sample for Cu2+ ions was increased significantly. Therefore, the results indicated that Ce-Cs /PAAM double network hydrogel may be a promising Cu2+ ions adsorbent.