The invention discloses a plasmon effect-based electric field-assisted method for repairing self-morphology of Ag nanowires. A technological process that the light combined with an electric field is applied on the surface of the Ag nanowire is adopted. By means of a simple fluid spreading process, the Ag nanowire is placed between silver film electrodes by being stirred by an atomic force microscope probe, and the surface of an Ag nanowire sample located between the silver film electrodes is repaired by applying both the light and the electric field at the same time. The defect of the surface of the Ag nanowire at a depth of 10 nm can be repaired by the technology, the repaired surface morphology of the Ag nanowire is close to or reaches the original morphology, and a new technical means is provided for improving the repair accuracy and efficiency of metal nanostructure defects.