Abstract: According to GB/T 13609-2017 "Natural Gas Sampling Guidelines", the classification of natural gas sampling methods, their respective technical characteristics, and industry applications are introduced in detail, especially the use of indirect sampling methods in natural gas analysis and testing is comprehensively analyzed and studied. The influences of different sampling methods on the analysis results were explored by using three sampling methods: aeration method, controlled flow method, and prefilled helium gas method. The results show that the aeration method is simple to operate and has little influence on the analysis results, which can be applied to the indirect sampling of natural gas.