The　strategy　of　intensifying　toluene　absorption　with　pi-electron　donor-based　deep　eutectic　solvents　(DESs)　is　first　proposed　and　systematically　investigated　from　the　molecular　mechanism　to　absorption　performance.　A　series　of　DESs　with　benzyl　as　a　pi-electron　donor　by　combining　hydrogen　bond　acceptors　(HBAs,　i.e.,　TEBAC,　TEAC　and　TAAC)　with　hydrogen　bond　donors　(HBDs,　i.e.,　EG,　LA　and　PhOH)　are　prepared.　The　absorption　performance　of　toluene　in　DESs　are　measured　experimentally,　and　the　result　demonstrates　that　TEBAC　+　PhOH　(1:3)　has　the　highest　absorption　capacity　(304　mg/g　at　298.15　K)　among　all　the　DESs　studied　in　this　work.　The　microscopic　mechanism　of　toluene　absorption　is　explored　by　(HMR)-H-1　and　FT-IR　spectra　and　quantum　chemical　(QC)　calculations.　The　reason　that　intensifying　toluene　absorption　is　the　pi-electron　donor　can　both　enhance　the　original　OH　center　dot　center　dot　center　dot　pi　and　C-H　center　dot　center　dot　center　dot　pi　interactions　of　HBD/HBA-toluene　and　add　an　extra　pi-pi　interaction　with　toluene.　This　work　provides　a　theoretical　guideline　to　develop　and　search　task-specific　DESs　for　efficient　toluene　absorption.