The utility model relates to a wagon top sliding hydraulic bracket for passing of a high-voltage cable. The wagon top sliding hydraulic bracket comprises a wagon top framework, a wagon top front support leg, a wagon top back support leg, a front bracket, a back bracket and a support leg connecting plate, wherein the wagon top framework is fixed on a wagon top; the front bracket and the back bracket are arranged on both sides of the front end and the back end of the wagon top framework respectively; both sides of the support leg connecting plate are hinged with the upper ends of the wagon top front support leg and the wagon top back support leg respectively; the lower end of the wagon top front support leg is hinged with the front bracket on the wagon top framework; and the wagon top back support leg is fixed with the back bracket through a bolt. Due to the adoption of the scheme, the erection working effect and efficiency of a bypass cable are improved, the overhauling and recovery service work of a distribution network line can be performed more quickly, the erection time of a bypass high-voltage cable is shortened from 2 days to only 1 hour, the span of an overhead line is over 30 meters, the distance between the overhead line and the ground is over 5 meters, and full adaptation to the conventional traffic route can be realized.