<p>Compared with non-gas-bearing strata, the surface subsidence induced by double-line shield tunneling in gas-bearing strata exhibits distinct characteristics, but there remains a gap in related research. This study uses Hangzhou Metro as the engineering carrier and combines long-term surface deformation monitoring with FLAC3D numerical simulation to first-ever reveal the surface subsidence patterns of double-line shield construction in gas-bearing strata. The main conclusions are as follows: (1) In the gas-bearing stratum influence zone, the surface subsidence and soil loss rate caused by the leading-line shield construction are significantly higher than those of the trailing line, differing from the patterns observed in conventional soft soil areas. More specifically, the average subsidence of the leading line is approximately 44% higher than that of the trailing line, while the soil loss rate is about 50% higher, and the subsidence trough of the trailing line is shallower. (2) A “three-stage disturbance” mechanism for gas-bearing strata is introduced: soil gas exhaust leading to soil structure degradation (primary disturbance), leading-line excavation-induced disturbance (secondary disturbance), trailing-line excavation superimposed disturbance (tertiary disturbance). (3) The underlying mechanism of the “intermediate gas pressure zone” is revealed: the incompletely released gas phase generates matrix suction, which amplifies the construction-induced disturbance of the leading line. These findings offer valuable insights for optimizing shield construction parameters and controlling subsidence in gas-bearing strata.</p>