Curtain grout technology was used in the project of surfaca subsidence control and ground water cut-off in Tonglushan mine. Considering typical grout characteristics under dynamic ground water new grout technologies were used in the project, prevention of liquid loss, control of liquid diffusion area and grouting sand layer in karst all have succeeded. Such technologies as cemant-sodium silicate double liquid grouting used, leakage sealing with kilp and grouting through drill stem obtained good results in the laboratory and field experiments. Successful applicatron of these new technologies further increased technical level of curtain grout and provided practical and effective methods for prevention of surface subsidence and reduction of water flow rate in a big water flow rate mine under complicated geological condition.