The utility model relates to a fixing device of a locomotive ground rod. The fixing device comprises an upper clamping plate, a lower clamping plate, screw rods and nuts which are matched with the screw rods to fasten the upper clamping plate and the lower clamping plate, wherein first notches are formed in the upper clamping plate and the lower clamping plate along the width directions, and first notches of the upper clamping plate and first notches of the lower clamping plate are matched with each other to form a bayonet for fixing the ground rod; second notches are correspondingly formed in at least one corresponding ends of the upper clamping plate and the lower clamping plate; the first ends of the screw rods are located in the second notch of the lower clamping plate and hinged to the lower clamping plate, so that the screw rods can rotate towards an opening direction of the second notch of the upper clamping plate, and the second ends of the screw rods can stretch above the upper clamping plate when the screw rods rotate in the second notch of the upper clamping plate. The fixing device disclosed by the utility model can be used for conveniently disassembling and assembling the ground rod.