Abstract: Based on the third\|phase project of Chengdu Metro Line 6, targeting mudstone stratum, sandstone stratum and high gas stratum, comprehensively considering factors including safety, economy and applicability, three construction methods of shield tunneling, mining and open excavation are comparatively analyzed, and different excavation schemes are discussed taking test section as object. Results show that applying combination of mining method and open excavation method to the construction of metro high gas tunnel section by section can effectively reduce construction risks. Compared to drilling and blasting method, boom\|type roadheader method has significant advantages in construction efficiency, quality and safety, but the construction cost is relatively high.