Abstract: The development of separation of CH4/N2 in coal-bed methane was reviewed. The main methods used in separation of CH4/N2 were discussed，including cryogenic distillation，pressure swing adsorption and membrane separation. The advantages and disadvantages of these methods in practical applications were compared，and the research results in different conditions were also analyzed. The prospect of separation of CH4/N2 in coal-bed methane was presented.