Methanotrophs (methane-oxidizing bacteria) can degrade methane into carbon dioxide and water. In this paper, several types of methanotrophs have been successfully cultivated and sorted out based on microbial technology, and the processes and approaches used are described in detail. By using several types of active methanotrophs, a few groups of experimental investigations have been carried out to determine their degradation effects on methane gas; these studies used different low methane concentrations that were less than 1.5%. The experimental results showed that the methanotrophs studied can still show the characteristics of normal activity under the conditions of a series of low methane concentrations that ranged from 0.25 to 1.5%. In the degradation process, with the increased methane concentrations in the mixed gas, more methane could ultimately be degraded to carbon dioxide. The decrease in methane and increase in carbon dioxide presented approximately linear relationships, and the numerical relationships between carbon dioxide and methane and the microbial degradation times could be described by exponential functions with high correlations. The conclusions in this paper attempt to forge a new path for the prevention of exceeding limited methane concentrations during coal mining by the use of microbial technology.