Abstract: To study the efficiency of flue gas sequestration with enhanced shale gas recovery in quartz slit, Grand Canonical Monte Carlo (GCMC) and Molecular Dynamics (MD) simulations were adopted to investigate the influence of burial depth, formation water content and the injection ratio of flue gas on the recovery efficiency of shale gas (CH₄) in quartz slit by flue gas (CO₂/N₂). The density distribution, loading, adsorption heat and interaction energy of each component were systematically analyzed to reveal their adsorption mechanisms and the recovery efficiency of CH₄. It indicates that the loadings of mixed CH₄ and N₂ (Γ_CH4 and Γ_N2) exhibit negative correlation with formation water content. With the increasing burial depth, both Γ_CH4 and Γ_N2 increase at first and then tend to be constant when the burial depth is over 2 400 m. The maximum loading of CO₂ (Γ_CO2) occurs at the burial depth of 2 400 m. There is a positive correlation of Γ_CO2 with formation water content when the burial depth is below 2 400 m, and a negative correlation when the burial depth is over 2 400 m. The recovery efficiency of CH₄ (η) reaches the maximum point at the burial depth of 400-600 m, which increases with the increasing mole fraction of CO₂ in flue gas, showing that CO₂ in flue gas can promote the displacement of CH₄ significantly.