3D braided material based on space group P3 symmetry has not been used in industrial production although the braided fabric has been proved to have excellent properties. Considering that plate 3D braided fabric iswidely used in some fields, the processing of plate 3D braided material based on space group P3 is first proposed. Based on the novel geometry structure of space group P3 symmetry, the yarn arrangement and motion law of the carriers of plate 3Dbraidedmaterial are studied. The fiber volume percentage and its variation tendency of the plate 3D braided material are predicted by establishingmathematicalmodel. Plate 3D braided material based on space group P3 symmetry has excellent properties and lays the foundation for industrial applications.