Abstract: The preparation methods of metallographic samples of Pb-Bi alloy were studied, and the effect of mechanical polishing and electrolytic polishing was compared. The real microstructure of Pb-Bi alloy was obtained through changing the polishing process parameters. The results show that:in the electrolyte of perchlorate and glacial acetic acid with volume ratio of 3:7, metallographic samples without deformation layer could be obtained by electrolytic polishing when the electrolytic voltage was 1~8 V and the time was 2~10 s. Compared with that of the mechanical polishing method, the time of electrolytic polishing method was less, and the efficiency was higher, and the microstructure morphology quality of obtained metallographic samples of Pb-Bi alloy was also better.