The invention belongs to the field of electrical equipment, and relates to a sliding high voltage cable floating combination fixing device which comprises a lower plate component and an upper plate component connected to the surface of the upper portion of the lower plate component. A cable clamp is fixed on the top face of the upper plate component. The lower plate component comprises a bottom plate, a lower guide rail arranged on one side of the surface of the bottom plate, and a lower connection seat arranged on the other side of the surface of the bottom plate. The upper plate component comprises a top plate, an upper guide rail arranged on one side of the bottom face of the top plate, and an upper connection seat arranged on the other side of the bottom face of the top plate. The sliding high voltage cable floating combination fixing device is reliable in effect, when the sliding high voltage cable floating combination fixing device is used, cable moving can be limited in the vertical direction, and disorderly deviation can not occur; meanwhile, due to the effect of a spring, when a cable ascends through thermal stress, spring force can effectively counteracts the weight of the upper plate component, and resistance of the cable in the ascending process can not be increased.