The invention provides a method to prepare lead metallic phase sample, which comprises: coarse grinding: using 320#-600# carbofrax emery paper and water as lubricant, then using carbofrax emery papers of 1000#, 1500# and 2000# to grinding; midst grinding: clearing the sample in supersonic device, polishing with polished cotton flannel; final grinding: clearing the sample in supersonic device, polishing the sample for 20-60s to drop 40ml H2O2+40ml CH3COOH etchant on new flannel; then, cleaning the sample, drying, and obtaining the final sample. This invention is simple but high definition. |