Abstract: Multi-source gas supply is an inevitable trend for the future development of city gas, so it is necessary to formulate the principle of gas interchangeability in order to ensure the safe and environmental usage of all kinds of gas. In this paper, the typical atmospheric gas appliances were selected by taking Beijing's multi-source gas supply pattern as an example. The simulated gas source was prepared using the high-precision dynamic gas distribution system, and the adaptability area of gas appliances from the aspect of gas quality was experimentally measured. It is shown that some gas appliances present the phenomenon of excessive CO emissions, so the corresponding measures shall be taken to avoid potential hazards. The long-term planned LNG sources in Beijing are distributed outside the gas appliance interchange areas of Beijing. If they are directly replaced with the reference gas of Beijing, the gas appliances of most residents will produce excessive CO emissions, indicating that the gas interchange is unavailable. The other planned gas sources in Beijing are all distributed in the interchange areas, indicating that the gas interchange is available. The research results are expected to provide a certain reference for the practical gas interchange in domestic and foreign cities and the production and operation of gas enterprises.