Abstract: There is a high dimensional accuracy requirement for inner surface of E shaped waveguide component for rader use.Now mainly using machining to produce such parts, the material utilization ratio and productive efficiency are very low.Based on the technology of precise plastical forming, the die is designed by CAD/CAE/CAM, and precise backward extrusion process for E shaped waveguide component has been developed.The result shows that through analyzing and controlling the process parameters, defects can be avoided effectively, qualified waveguide components are produced stably, and the microstructure of part is refined and compacted;In addition, the man-hours are decreased by 85% and the materials are saved at 81.7%;The new forming technology for this E shaped waveguide component has the advantages of high quality, high efficiency, low cost and low pollution.