Many early surface coal mines in China are deep and concave open-pits, and do not fit for dump. They will become an enormous pit when the mine is closed. Because the slope and the groundwater can not be maintained, the open-pit would cause geological and environmental calamities. The backfill open-pit is an effective measure for resolving the problem. The overburden of the neighboring producing surface mine provides the backfill material, and with the launder technology, the material transportation will be carried out by the help of the material weight, with a greatly reduced transportation cost. As an example, the backfill technology of the FUSHUN west open-pit is studied, and the reasonable backfill technology is proposed.