Abstract: Maize stalk defoliator is an agricultural equipment for maize defoliator. The useless stems and leaves are removed by the elastic defoliator blades on the defoliator wheel, and does not destroy the tissue structure of the stem. The structure of the part is complex, the parts can not be processed on the general fixture and machine tool, so special fixture must be designed to ensure the smooth processing and precision. In this paper, a special fixture is designed for the impeller, which can process the part conveniently, accurately and in batches.