The invention discloses a conductive plugging slurry and a preparation method and application thereof. The conductive plugging slurry comprises the following components in mass percentage: 0.5 to 5% of graphene, 50 to 80% of metal conductive powder, 10 to 30% of resin, 1 to 5% of curing agents, 0.1 to 3% of auxiliaries, and 1 to 10% of solvents. In addition, the preparation method includes: preparing a graphene conductive slurry; preparing a metal powder conductive slurry, and mixing the graphene conductive slurry and the metal powder conductive slurry. The conductive plugging slurry has the uniform and stable slurry dispersion system; and the storage time is long. After solidification, the formed conductive plugging solidified film has stable conductivity, high-temperature-resistant and heat-resistant characteristics, and high stability; and a breaking phenomenon is avoided.