The toughening modification of epoxy resin (EP) has been accompanied by its application and development. Nano particles toughened EP has unique properties. Janus nanosheets with different compositions on both sides have high specific surface area, rich surface functions, and strong interfacial adhesion with epoxy matrix. In this paper, anisotropic Janus nanosheets based on silica were prepared by emulsion interface sol-gel method and used to toughen EP. Results show that JNS solid particles can toughen and strengthen EP at the same time. Both sides of JNS2 can participate in the crosslinking of EP, so JNS2 is embedded into the three-dimensional polymer skeleton network. However, only the amino group on the hydrophilic side of JNS1 can participate in the crosslinking of EP. As a result, JNS2 has better toughening and strengthening effect than JNS1. When the mass fraction of JNS2 is 0.5%, the impact strength and the elongation at break of EP/JNS2 are 57.08% and 58.68% higher than those of pure EP, respectively. All of the rigidity, the glass transition temperature and thermal stability of EP/JNS composites are increased slightly.