Abstract: The filling pattern of mixed slurry cementing composed of full tailings and classified tailings has been adopted to give full play to complementary advantage of full tailing mortar and classified tailing cemented in filling technology.To realize the rapid and accurate control for the field control parameters and ensure the system' stability and continuity，S7-300 type PLC has been employed as the controller.The PLC application program has been programmed according to intelligent algorithm which combined with classical control and intelligent control to monitor and control various operating parameters in system.By configuration software in the upper computer，the PC monitor interface has been designed to display the real time operating parameters.The experimental results show that the system parameters can be quickly and accurately measured，and the parameters，such as the concentration and the flow of filling tailings slurry be effectively controlled.The problems of large delay and low control precision have been well solved.It meets the requirements of process control，and has a good application prospect with producing cost greatly reducing.

Key words: Full tailings, Classified tailings, PLC, Composite control, Monitoring