Abstract: The crushing systerm in the underground is built at the deep mining of Baoshan Mine，and two-stage crushing on underground waste-rock is made with jaw crusher and compound crusher  The dewatering screen is adopted to take off watery slurries from the first crushing，which is effective to solve the blocking problem of compound crusher in high watery waste-rock breaking.And ventilating and dusting system with the hermetic and half hermetic way is applied to purify the air dust of the crushing cave.It realizes to treat waste-rock on-site，and directly use the crushed stone aggregate into the cemented filling in the stope.

Key words: Deep mining, Waste-rock in the underground, Crushing system, Dewatering mesh vibration screen, Dust removal by hermetic ventilation