In the vacuum interrupters, high-current vacuum arcs deliver a large amount of energy to the contacts. When the arc current is high enough, the contacts surface experience severe erosion and the contact performance will be reduced significantly. The objective of this paper is to study the influence of high current vacuum arc on the alloy structure. In the experiments, the drawn vacuum arc is organized the a high speed camera is used to observe the surface morphology of the contacts. Then, conduct scanning electron microscopy experiments on the contacts after the experiment to analyze the erosion effect of the arc to the abode. Both the anode thickness and the particle size are measurement. The particle size differences between the original alloy and the melting layer are also determined.The research results of this paper contribute to to get a deeper understanding of the anode erosion mechanism.