Abstract: In the processing of thin-walled parts, clamping, cutting deformation and insufficient rigidity are common technical problems. For the weak rigid thin-walled parts whose rigidity can not meet the processing requirements, special clamps are often used as supporting tools. But in the small batch production and single piece production, the cost of customized special fixture is too high. In view of this kind of situation, this paper proposes to use oil mud as the support material of the inner cavity of the thin-walled parts to improve the system rigidity of the thin-walled parts. It has been proved by experiments that the sludge filling support can replace the special fixture support very well, and the sludge filling support also has the advantages of reusability, not limited by the contour of the inner cavity of the parts, which can greatly reduce the production cost, and has certain guiding significance for the production of enterprises.