The invention provides a gear-shifting operating mechanism for a heavy truck transmission, and the gear-shifting operating mechanism is applied to the technical field of heavy truck transmissions. One end of a gear-shifting operating rod (1) is connected to a mounting base (3); the other end of the gear-shifting operating rod (1) is movably connected to a telescopic pole assembly (4); the position at the lower end of the gear-shifting operating rod (1) is provided with a projecting lower end flange (6); a lock hook rotary shaft (7) is arranged on the telescopic pole assembly (4); a lock hook flange (8) is arranged on the lock hook rotary shaft (7); a lock hook (9) is arranged to be a structure capable of being hooked into a groove (11) in the telescopic pole assembly (4); and a return spring (10) is arranged on the lock hook rotary shaft (7). According to the gear-shifting operating mechanism, when a cab of the heavy truck is not turned over, positioning of the telescopic pole assembly can be realized; when the cab of the heavy truck is turned over, three-layer stretching-out drawing-back of the telescopic pole assembly can be reliably realized to meet cab turnover needs; and meanwhile, a gear-off phenomenon, in a travelling process, of the transmission can be prevented.