Abstract: In view of problem of actual application requirements of a safety monitoring and control system in Xiezhuang Coal Mine, opening control of the system was used to extend other functions, namely adding automatic water supplement device of pipe reducing valve, automatic monitoring device of dustproof water, water pressure monitoring device of dustproof pipe and automatic operating device of exhausting ventilator. Working principle and application effect of the above devices were introduced. The actual application showed that the development of the above functions expands monitoring range of the safety monitoring and control system and improves automation level of mine.