The utility model provides a detaching-buckling device for a steel ladle heat-preserving cover. The detaching-buckling device for the steel ladle heat-preserving cover comprises a support guide rail, a slide component, a first linear-motion perform component, a second linear-motion perform component, at least one hook, a lifting wheel, and a control system. The support guide rail is installed on an appropriate position above the top end of the steel ladle, the slide component can move along the support guide rail, the first linear-motion perform component is horizontally arranged on the support guide rail and is connected with the slide component, and the second linear-motion perform component is disposed on the slide component. The at least one hook is used for hooking a lifting ring on the steel ladle heat-preserving cover, and is connected with the second linear-motion perform component through a connecting component. The lifting wheel is arranged on the slide component, and is used for leading the connecting component from the horizontal direction to the vertical direction. The control system is used for controlling operation of the first linear-motion perform component and the second linear-motion perform component. The detaching-buckling device for the steel ladle heat-preserving cover has the advantages of being simple in structure, flexible and convenient to use, wide in use range, and strong in practicality.