Abstract: The electron transfer process of microbe on the mineral surface was studied by the use of a microbe fuel cell. The results indicate that direct contact plays an important role in the process of reducing Fe(OH)₃ with Geobacte metallireducens, and the bio-film absorbed on the mineral surface is a key factor. Bio-film formation needs a relative long time. It is an important metabolic way to form bio-film by cell-absorption on the solid surface. Although mediate AQDS accelerates the reduction rate effectively at the early stage, but its effectiveness is not significant after the cell-absorption. So the microbe catalysis mineral oxidation-reduction reaction is influenced by bio-film. Accelerating the film formation on the mineral surface and keeping its stability are very important for the microbe leaching rate.