A voltage-sharing cover assembly is used for realizing uniform distribution of electrical stresses which surround an electric device possessing a cylindrical end. The voltage-sharing cover assembly comprises a clamping component and a voltage-sharing cover, wherein the clamping component is constructed to clamp the cylindrical end along a circumferential direction of the cylindrical end; the voltage-sharing cover comprises a slope-shape cavity possessing two opening ends; the voltage-sharing cover also comprises a connection component; the connection component is fixed in the slope-shape cavity and is connected with the clamping component in a mode that the voltage-sharing cover is detachably fixed on the electric device and the cylindrical end portion of the electric device is at least partially extended into the slope-shape cavity of the voltage-sharing cover through one of the opening ends.