Silver nanowires (AgNWs) have received much attention due to their excellent optical, electrical, and conductive properties. In this work, we provided a new perspective for investigating the property of AgNWs from a single nanowire level. Single Ag nanowire electrodes and single Pt@Ag nanowire electrodes were fabricated by a laser-assisted pulling technique and galvanic replacement reaction (GRR). The radius, length, and metal ratio of the nanowires are tunable as needed. The prepared nanowire exhibited excellent electrocatalytic activity toward the methanol electro-oxidation and high sensitivity for monitoring the reduction of 4-nitrothiophenol by recording SERS spectra. This work will help us deeply understand the catalytic performance at the single nanowire level and open a new perspective for nanomaterials research.