As an important sub-system of mine drainage system, monitoring system played a decisive role in ensuring the stability and reliability of the system and improving the safety of underground drainage operation. Xinzhi Mine was taken as an example, the existing problems of drainage monitoring system were emphatically analyzed. The improved design of the monitoring system was carried out from the aspects of the overall scheme of the monitoring system, the control strategy of water pump rotation, the main control chip, etc.. It was concluded that the improved new system had higher monitoring performance, more comprehensive functions, and higher intelligent degree of operation data collection, it achieved the expected design effect and system promotion conditions, which was of great significance to improve the operation efficiency and safety of the drainage system in the mine.