A new type of water-retaining, slow-release fertilizer (WSF) based on double-network hydrogels wasfabricated via the ion-crosslinking of sodium carboxymethyl cellulose and the free radical polymeriza-tion of polymerizable β-cyclodextrin (MAH-CD), polyethylene glycol dimethacrylate (PEGDA), acrylamide(AM), and acrylic acid (AA) with urea-loaded halloysite as an additive. The effects of the AM to AAmonomer ratio, the halloysite content, the AlCl3 content and the MAH-CD content on the swelling ratiowere studied. Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), andthermogravimetric analysis (TGA) were applied to characterize the structure and properties of the WSF. The swelling behavior and water retention capacity of the fertilizer were investigated using a classicgravimetric method. The experimental results indicated that the presence of halloysite nanotubes clearlyadjusted the swelling and release properties of the WSF. Kinetic modeling indicated that the swellingmechanism and slow release behavior were consistent with a Fickian diffusion mechanism. Form theconsiderations of its properties and raw materials, the fertilizer developed here has a good prospect ofapplication and extension.