Abstract: The bombarded LaB₆ cathode is a new type of cathode applied in the electron gun.It has not only a good structure in optics system,but also the powerful ability of emission and has a great important significance in developing and researching the high-power electron gun.The principle of the work,the significance of the study,the selection of the material of the cathode was dealt with in this paper.This task based on investigation has completed the design and calculation of bombarded cathode,it has designed and completed the experiment equipment of the bombarded LaB₆ cathode.By the experiment,we found that the bombarded LaB₆ cathode could get the maximum of emission current that is (450 mA,) when the cathode temperature got to 1 843 K.Moreover,by analyzing the datum of the experiment,we got the constant A of LaB₆ emission that is 21.33 and the function Φ_s of it that is 2.6 eV,which are quite similar with the theoretic value,and proved the experiment had veracity and reliability.