The invention discloses a rubber vibration isolator for a rail transit floating slab track bed vibration isolation system. The rubber vibration isolator comprises an upper cover plate, an upper iron part, a rubber part, a lower iron part, a lower seat plate, an iron core, a limit bolt and a locking plug screw, the upper cover plate, the upper iron part, the rubber part, the lower iron part and the lower seat plate are sequentially connected, the upper cover plate is detachably connected with the upper iron part, the upper iron part, the lower iron part and the rubber part are integrally vulcanized, the lower seat plate is detachably connected with the lower iron part, the iron core is arranged in the rubber part, the iron core and the rubber part are integrally vulcanized, the limit bolt sequentially penetrates the upper cover plate, the iron part, the rubber part and the lower iron part and is connected with the upper cover plate in a threaded manner, and the locking plug screw is connected with the upper cover plate in a threaded manner and abutted to the top face of the limit bolt. The rubber vibration isolator is high in bearing capacity, fine in fatigue resistance, simple in structure and convenient to manufacture, mount and maintain and has fine vibration isolation performances, and vertical limit and radial limit can be realized.