The invention discloses a steel structure skid frame for an ingot blank combined water-cooling casting device. The steel structure skid frame surrounds the outer side of a combined crystallizer of the ingot blank combined water-cooling casting device and comprises upright columns which are arranged at intervals relative to the outer side of each water cooling plate assembly forming the combined crystallizer; a first rectangular ring hollow skid surrounding the combined crystallizer is fixedly supported at the upper end of each upright column; the lower end of each upright column is fixedly connected with a second rectangular ring hollow skid surrounding the combined crystallizer; a main water inlet pipe is arranged on the first rectangular ring hollow skid; a main water return pipe is arranged on the second rectangular ring hollow skid; the first rectangular ring hollow skid is communicated with a water inlet of each water-cooling plate assembly through a pipeline; and the second rectangular ring hollow skid is communicated with a water outlet of each water-cooling plate assembly through a pipeline. The steel structure skid frame greatly reduces the number of pipelines and structural complexity, and makes operation convenient and fast; and each water-cooling plate assembly is controlled by an electrohydraulic push rod compression system, and a tank can be opened at high temperature conveniently.