The invention discloses a live polishing device for a substation disconnector contact. The live polishing device is characterized in that a polishing executing component comprises a hydraulic motor fixed on a workbench, a transmission flexible pipe connected with the hydraulic motor, a main insulating rod connected to the transmission flexible pipe and fastened to a clamping block and a polishing wheel connected to the main insulating rod, the rotation speed of the polishing wheel is adjustable, and the hydraulic motor rotates to synchronously drive the transmission flexible pipe and the main insulating rod to rotate so as to allow the polishing wheel to rotate to perform polishing. The live polishing device has the advantages that the automation level and polishing efficiency are further increased, probability that staff enters a substation equipment region is reduced, operator safety is guaranteed, and potential safety hazards are eliminated; the live polishing device is simple in structure and convenient to assemble and maintain.