The invention relates to a photoelectric composite enameled wire based on a novel sensing technology and a preparation process, and belongs to the technical field of power transformer winding wire manufacturing. A single-mode optical sensing element is placed in a groove of a special-shaped copper conductor wire. An insulating paint film uniformly covers the surface of the special-shaped copper conductor wire. A self-adhesive paint film uniformly covers the surface of the insulating paint film. The single-mode optical sensing element and the special-shaped copper conductor wire are bonded intothe integral photoelectric composite self-adhesive enameled wire. According to the invention, the single-mode optical sensing element is preset in the enameled wire for manufacturing a transformer winding, so that a transformer fault online early warning system can be established. The enameled wire can continuously realize close combination of the single-mode optical sensing element and the conductor wire. The transformer winding wire has a continuous sensing function, online detection can be implemented, power transformer fault diagnosis can be accurately forecasted, meanwhile, the transformer winding wire has the functions of electric conduction and winding operation information sensing, and sudden accidents of a power grid can be avoided or reduced by taking effective measures.