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研究大电流真空电弧形态和等离子体参数的演变过程对于进一步理解真空电弧具有重要意义。该文采用 Ansys计算分析了真空灭弧室中杯状电极和1/3匝线圈电极间的纵向磁场。分别计算了在峰值时刻，电弧初始扩散2ms 内电极间的纵向磁场分布。计算结果表明，杯状电极间纵磁呈钟形分布而线圈式电极类似马鞍形分布。在电弧初始扩散阶段，电极间纵向磁场很弱，纵磁随时间增大。利用以上磁场分布，对两种大容量电极进行磁流体建模和仿真，在大开断电流条件下，与杯状电极比较，线圈电极沿径向扩散更明显。随着电弧的扩散，电流密度的分布更加均匀，离子温度最大值由阳极中心转移到弧柱边沿，电子温度在整个电弧中趋于3eV。将仿真结果与弧柱图像作对比，计算光强的变化与弧柱亮度变化一致。“,”The research of evolution process of high-current vacuum arc and its plasma parameters is crucial to understand vacuum arc mechanism. The axial magnetic field (AMF) distributions of cup-shaped electrode and coil-shaped electrode were simulated by Ansys software at the peak-value moment and within the initial arc diffusion period (2ms). According to the simulation results, the AMF generated by cup-shaped electrode presents a bell-shaped distribution while 3 segments coil-shaped electrode generates a saddle-shaped distribution. During the initial diffusion period of arc, the AMF between the electrodes is very weak and it increases with time going on. A magneto-hydro- dynamics (MHD) behavior of two kinds of high-capacity electrode was simulated according to the aforementioned AMF distribution. Under a high-current interruption condition, the AMF of coil electrode shows a more significant diffusion as a contrast to cup-shaped one. With the arc diffusing, the current density distributes more uniformly and the maximum value of ion temperature moves to the edge of the arc from the center and the electron temperature tends to be 3eV. The simulation results are compared with experimental results, which show that the light intensity change of simulation is in accordance with arc luminance.