After converting the main production from the surface mining to under-ground, Baiyin Nonferrous Metals Co launched an effective technical reform in mining method and equipment in Xiaotieshan Lead-zinc mine and Deep Copper mine which are ad-ministered by this company, made a study of the regularity and control techinque of earth pressure activity in rerearch. These important measures have promoted a technical ad-vancement of mine powerfully, and enhanced a production capacity of mine and their econ-mic benefit.