Abstract: Based on the quality characteristic of current coal-based substitute natural gas (SNG), the composition, high calorific value, interchangeability and water dew point for coal-based SNG are presented. The comparison between coal-based SNG and conventional natural gas is completed comprehensively, and essential property and fuel gas quality of coal-based SNG are pointed out. It is illustrated that there is no constrained problem for coal-based SNG incorporation and interchange application with traditional natural gas, and the coal-based coal-based SNG is clean fuel gas in high quality as a beneficial and necessary supplementary for conventional natural gas. This paper provides references for coal-based SNG promotion and application as a new kind of clean energy resource, and coal-based SNG quality standard establishment.