Cooperating with Baiyin Nonferrous Metals Industry Incorp, Changsha Institute of Mining Reseach conducted a study on the automatic control system of cemented filling.We have studied the automatic conrol for fill slurry concentration, agitating-tank liquid Level and cement-sand ratio, monitoring and displaying on the screen the varied technological paraneters in cemented fill preparation process, and printing display of the accumlative sum of cement and fill slurry. This paper describes the design of inspecting and detecting instruments for this system, the establishment of control model, the design of hardware and software for STD commercial controller, and the whole ystem operating situation.