The invention discloses a direct-acting disconnecting switch operation mechanism. The direct-acting disconnecting switch operation mechanism comprises a gear A, a gear B, a transition gear, a rod A, a rod B, a disk, a power transmission device and a frame. The disk is rotationally installed in the frame through a shaft. The rod A is fixed to the disk in the radial direction. The gear A is fixedly installed on the top of the frame and located above the disk. The transition gear is movably connected with the rod A through a cylindrical pin and meshed with the gear A. The gear B is movably connected with the rod A through a cylindrical pin and meshed with the transition gear. One end of the rod B is hinged to the rod A and fixedly connected with the gear B, and the other end of the rod B is connected with an insulation pull rod of a disconnecting switch body through a blend board assembly. The power transmission device is connected with the shaft. The rod A and the rod B are equal in length, and the ratio of the number of teeth of the gear A to the number of teeth of the gear B is equal to 2. By means of the direct-acting disconnecting switch operation mechanism, under the situation that the isolating fracture is larger than 150 mm is guaranteed, the overall size of a disconnecting switch can be effectively reduced.