The utility model discloses a clamping supporting seat, which comprises a clamping supporting seat body, interchangeable connectors and adjusting bolts, wherein a plurality of step holes are opened on the clamping supporting seat body, the interchangeable connectors are detachably arranged inside the step holes, threaded holes are opened on the interchangeable connectors, and the adjusting bolts are in threaded fit with the threaded holes for tightly compressing a component to be machined. In the clamping supporting seat, the purpose of clamping a workpiece is realized through the matching of the adjusting bolts and the interchangeable connectors by opening the step holes on the interchangeable connectors and detachably mounting the interchangeable connectors inside the step holes. The clamping supporting seat is simple in structure and convenient to mount and manufacture. The interchangeable connectors can be separated from the clamping supporting seat body to choose a material with higher fatigue strength and toughness; therefore, the service life of the whole clamping supporting seat is prolonged, and the manufacturing cost of the whole clamping supporting seat is not greatly increased; and simultaneously, after the screw threads of the interchangeable connectors is worn, just the interchangeable connectors can be changed without changing the whole clamping supporting seat, so that the maintenance cost is greatly reduced.