In the Deep Copper Mine of Baiying Nonferrous Metals Corporation, the tailings cemented backfill mining system has been adopted in which density meter,differential pressure liquid level meter,intelligent solid flow meter,electromagnetic flow meter and weight-loaded level indicator are installed on-site to on-time measure the tailings discharge concentration and the level of the vertical tailings bin, the liquid level,the tailings discharge flow and the concentration of the agitating tank, as well as the delivery flow of the cement bin. The analogue signals from these meters , after an A/D conversion, are sent to the control system for computerized control, display and calculation. The computer will compare the input with pre-set parameters. The calculation results, after D/A conversion, will be output as control signals which drive the execution system to regulate various physical parameters. Therefore, fully automatic monitoring and control can be realized for the preparation process of the filling slurry.