The invention discloses an electric polishing machine. The electric polishing machine comprises a supporting base, a first supporting plate body, a second supporting plate body, a supporting top plate, a first driver, a driving motor, a polishing wheel, a first supporting base plate, a second supporting base plate, a first supporting stand column, a second supporting stand column, a convex supporting base, a first bearing, a second bearing, a transmission rod, a transverse supporting plate, a supporting base and a cushion block; a second driver is installed on the upper surface of the cushionblock, and a sliding rail is fixedly arranged at the upper end of the transverse supporting plate; a sliding seat body is arranged at the upper end of the sliding rail in a sliding mode, a first clamping device and a second clamping device are installed on the sliding seat body, and the first clamping device and the second clamping device are used for clamping a sheet metal workpiece; and the polishing wheel is used for polishing the sheet metal workpiece. According to the electric polishing machine, on one hand, the ascending and descending height of the polishing wheel can be adjusted, and meanwhile, the height of the transverse supporting plate can be adjusted; and on the other hand, the transverse position of the sheet metal workpiece can be adjusted.