The rapid development of the world economy makes the demand for natural gas in a continuous uptrend. In order to improve the energy consumption structure, many countries are making efforts to develop coal bed methane, shale gas and other non-natural gas. Especially in recent years, each country has adopted a series of preferential policies to encourage the development and utilization of coal-bed methane. CBM (coal bed methane) can reduce greenhouse gas emissions, which can achieve safety production of coal mine and play positive role in developing a low-carbon economy. Therefore, Sichuan Changyi develops multiple-column cyclone gas-liquid separator in front section of producing process. This separator features small size, compact structure, small risk, high separation efficiency. In particular, the separation ，efficiency can be adjusted according to the gas flow rate .