Abstract: The natural caving mining method is adopted by Yechangping molybdenum mine, its bottom structure is layout in the extremely unstable oxidation ore in production process.Serious damage of the headings results that the ore drawing can not work normally.FLAC software is used to make numerical simulation to simulate the form of support and calculate the support parameters in order to contrast different schemes.This research provides an important basis for determining the support scheme and parameter.

Key words: Natural caving mining method, Extremely unstable ore, FLAC simulation