Provided is a method of preparing a nanocomposite material plated with a network-type metal layer through silica self-cracks and a wearable electronics carbon fiber prepared therefrom. The present disclosure provides a nanocomposite material having excellent electrical conductivity and bending resistance by plating a network-type metal layer on a substrate having a flat surface and/or a curved surface through a method of preparing the nanocomposite material in which the network-type metal layer is plated on silica self-cracks by applying a silica coating solution on the substrate having a flat or curved surface, performing drying after the applying of the silica coating solution to form the silica self-cracks having random crack directions and sizes, and performing electroless metal plating on the surface of the substrate. Further, the present disclosure provides a wearable electronics carbon fiber having excellent electrical conductivity and bending resistance.