The utility model discloses a gate seat hoist. The utility model belongs to the field of water conservancy and hydropower mechanical equipment. The trolley comprises a trolley frame, a trolley walkingmechanism, a portal frame and a cart walking mechanism, the device further comprises a cantilever crane, an electric hoist and a revolving platform, the end part of the arm frame is fixedly connectedwith a balancing weight; a trolley track is arranged on the side wall of the arm frame; the trolley travelling mechanism is suspended on the trolley track; the top of the trolley frame is connected with the trolley walking mechanism. Wherein the bottom of the trolley frame is connected with the electric hoist, the portal frame comprises a supporting platform, portal legs, a middle cross beam anda lower cross beam, a slewing bearing is arranged on the supporting platform, a motor, a first speed reducer and a pinion are fixed on the slewing platform, the motor is connected with the first speedreducer, the pinion is installed on the first speed reducer, and the pinion is meshed with the big gear. The cantilever crane can rotate freely in the whole horizontal direction, the trolley can walkin the axial direction of the cantilever crane, and therefore the cantilever crane can work in different hoisting ranges, and is high in flexibility and working efficiency.