A　novel　purification　technology　for　the　absorption　of　chlorobenzene　(CB)　using　carboxylic　acid　based　deep　eutectic　solvents　(DESs)　as　absorbents　was　proposed　and　systematically　investigated,　combining　experiments　with　microscopic　molecular　simulations.　A　series　of　newly　designed　DESs　synthesized　and　evaluated　for　their　CB　absorption　performance,　revealing　that　DESs　with　quaternary　phosphonate　as　hydrogen　bond　acceptors　(HBAs)　and　long-chain　fatty　acid-based　hydrogen　bond　donors　(HBDs)　exhibit　remarkable　CB　absorption　performance.　Additionally,　it　illustrated　that　both　the　structure　and　acidity　of　HBD　significantly　impact　the　absorption　capacity.　Consequently,　the　DES　comprising　tetrabutylphosphonium　chloride　([P4444][Cl])　and　decanoic　acid　(DecA)　with　molar　ratio　of　1:2　was　identified　as　the　possessing　optimal　absorbent.　Notably,　after　undergoing　five　cycles　of　absorption-desorption　processes,　the　CB　absorption　capacity　in　[P4444][Cl]-DceA　(1:2)　was　almost　maintained　at　approximately　467　mg/g　(Henry＇s　law　constant　of　4.90Pa　m3/mol)　at　30　degrees　C.　NMR　characterization　revealed　no　chemical　bonding　between　[P4444][Cl]-DceA　and　CB,　indicating　that　it＇s　a　physical　absorption　process.　Finally,　the　interaction　mechanism　was　elucidated　by　COSMO-RS　model,　quantum　chemical　calculations　and　wave　function　analysis.　This　work　fills　the　gap　of　CB　removal　by　DES　absorption　and　proves　that　DES　is　a　promising　green　solvent　for　the　removal　of　chlorinated　volatile　organic　compounds.