Based on the static electric-field simulation, the structures of 20 GW diode and its insulator, as well as the position and shape of guide magnetic-field are designed and optimized. Then the experiments on the repetition rate of intense current electron-beam diode are carried out on 20 GW pulsed power source, it can deliver intense electron-beam pulses of 1MV/20 kA with pulse width 45 ns and repetition rate 100Hz.