Abstract:Drainage of lakeside open-pit mine is an important work in mining process. With the increase of the depth of openpit mining area and catchment area, the catchment volume will increase and the difficulty will become greater. Taking Chengmenshan Copper Mine surrounded by three lakes as an example, the original drainage system of mining area was upgraded to a new drainage system in order to improve drainage capacity. After running for a period of time, it is found that there are some drawbacks in the installation process of the new drainage equipment. The optimization of drainage equipment installation process in this mine provides reference for drainage system of other open-pit metal mines.