The invention relates to a double-expander thin-walled part clamp. The clamp comprises a clamping tool body which is internally provided with a pull sleeve capable of moving front and back, an inner expanding sleeve directly connected with the pull sleeve and an outer expanding sleeve in sequence, a transition disc is installed on the outer side of the inner expanding sleeve and is connected withthe clamping tool body and a main shaft flange plate, a positioning disc is fixed to the tail end of the transition disc, and the outer expanding sleeve is arranged on the transition disc in a sleeving manner to sequentially penetrate an installing hole in the clamping tool body and a limiting disc through a pull nail. The double-expander thin-walled part clamp has the beneficial effects of beingreasonable in structure, high in positioning accuracy, high in finished product rate and the like, the problem about deformation during machining of a thin-walled part product can be effectively solved, quick clamping and positioning are achieved, the production efficiency and the machining function of a machine tool are greatly improved, the rejection rate is reduced, the production cost is reduced, and certain economic benefits and social benefits are achieved.