The structure of field emission triode is first simulated by MAGIC. The tip height, tip position, tip curvature, gate aperture, and gate voltage are changed, to observe the emission current and the electron congregation. 本课题首先采用MAGIC软件对三极管结构的尖锥场发射阴极进行了模拟计算,分别改变尖锥高度,锥尖位置,尖锥曲率半径,栅极孔径及栅极电压,观察阳极收集电流及电子束的会聚情况。