As　one　of　the　most　potent　greenhouse　gases,　SF6　has　a　significant　economic　and　environmental　impact　on　the　purification　and　recovery　of　exhaust　gases　from　the　semiconductor　industry.　The　adsorption　and　separation　performance　of　SF6　on　a　two-dimensional　covalent　organic　framework　TAT-COFs-1-AB　with　different　functional　groups　(-SO3H,　-Et,　-NH2,　-OMe,　-OH,　-H)　was　investigated　by　using　grand　canonical　Monte　Carlo　(GCMC)　simulations　and　density　functional　theory　(DFT)　calculations.　The　results　show　that　the　adsorption　at　low　pressure　depends　on　the　interactions　between　the　SF6　and　COF　frameworks,　while　at　high　pressure　it　is　mainly　affected　by　the　porosity.　The　highest　adsorption　capacity　of　8.44　mmol/g　(298　K,　100　kPa)　is　exhibited　by　TAT-COF-1-AB-H,　which　has　the　highest　porosity.　Chemical　functionalization　was　found　to　be　effective　in　enhancing　the　SF6/N-2　selectivity.　Among　all　the　functionalized　COFs,　TAT-COF-1-AB-NH2,　with　the　highest　specific　surface　area　and　strong　heat　of　adsorption,　showed　the　highest　selectivity.　The　simulation　of　self-diffusion　also　shows　consistent　results　with　the　GCMC　simulation.　The　findings　highlight　that　the　adsorption　capacity　is　influenced　by　substituent　and　porosity,　with　SF6　showing　a　consistent　preference　for　adsorption　at　hollow　sites,　as　evidenced　by　binding　energy　and　charge　transfer　analyses.