Abstract: This paper introduces the classification, basic composition and system topology of coal mine safety monitoring system, and compares the data acquisition methods of coal mine safety monitoring system. There are roughly three methods of data acquisition in coal mine safety monitoring system, i.e. master-slave (data acquisition by patrol inspection to sub-stations), multi-master (data transmission from node device initiatively upward) and their mixing methods. By comparing different data acquisition methods, the characteristics of different data acquisition methods are summarized, and the advantages and disadvantages of each method are obtained.