With the increasing power density of aerospace microwave devices, the possibility of multipactor effect in microwave devices is greatly increased. In view of the potential threat that space electronics may induce the multipactor discharge in microwave devices, a special waveguide structure was designed to study the multipactor discharge. The electron gun provided electron into special waveguide when high power microwave signal were introduced into the waveguide. The power detector and oscillograph were used to detect transmission waveforms and reflection waveform respectively. The continuous process of multipactor phenomenon was obviously observed. This work verifies that electron beam can induce multipactor phenomenon and provides an important means to study multipactor effect of microwave devices.