Conventional hydrogels are mechanically too weak to be practically used in any stress or strain bearing applications, which limits extensive application of hydrogels as biomedical and other industrial fields. In this paper, we reported a novel hydrogels, poly(2-hydroxyethyl methacrylate-acrylamid)/clay(abbreviated as P(HEMA-AM)/Clay), with double-network (DN) structure and high mechanical strength. A series of double network poly(2-hydroxyethyl methacrylate-acrylamid)/clay nanocomposite hydrogels were prepared. In this case, the one network was crosslinked by clay as physical crosslinker, and the other network was crosslinked by N,N-methylenebisacrylamide (MBA) as chemical crosslinker. The prepared samples were characterized by Fourier transform infrared spectroscopy(FTIR), scanning electron microscopy(SEM). And the tensile and compressive strength tests were also studied. The results show that the prepared samples present a highly porous surface and quite good mechanical properties. In addition, the prepared hydrogel with high mechanical strength and porous structures has promising applications in the development of soft machine, biosensors, tissue engineering, bioseparation and other advanced materials.