Nitrile　butadiene　rubber　(NBR)　is　an　important　synthetic　rubber　made　by　copolymerization　of　butadiene　and　acrylonitrile.　The　hydrogenated　nitrile　rubber　(HNBR),　made　by　selective　hydrogenation　of　NBR,　not　only　maintains　the　original　oil　resistance　and　wear　resistance,　but　also　greatly　improves　its　weather　resistance　and　ozone　resistance　properties,　which　is　widely　used　in　weapon　parts,　aerospace　seals　and　other　fields.　It　is　a　key　hot　topic　for　the　chemical　modification　of　unsaturated　polymers.　In　this　paper,　we　systematically　investigated　the　influence　of　solvent　properties　on　the　dissolution　behavior,　size　distribution　molecular　structure　of　NBR　and　catalytic　performance　in　solvent　by　using　nanometer　particle　size　analyzer,　ubbelohde　viscometer　and　Fourier　transform　infrared　spectroscopy　combined　with　density　functional　theory　(DFT).　The　results　show　that　strong　electrophilic　solvents　cannot　dissolve　NBR,　but　electron　donating　solvents　and　some　weak　electrophilic　solvents　can　dissolve　NBR　well.　Especially　in　ketone　solvents,　NBR　has　small　particle　size　with　narrow　distribution.　DFT　calculations　reveal　that　compared　with　the　gas　atmosphere,　the　bond　lengths　of　C=C　double　bonds　in　NBR　segment　has　increased　in　all　solvents,　and　show　an　increasing　trend　as　the　polarity　of　the　solvent　increases.　The　dipole　moment　of　NBR　also　increases　with　the　increase　of　solvent　polarity.　Especially　in　ketone　solvents,　the　highest　occupied　molecular　orbital　(HOMO)　of　NBR　molecule　moves　from　the　edge　to　the　inside　of　the　molecule　under　the　strong　solvent　effect,　indicating　that　it　may　have　a　positive　influence　on　the　C=C　double　bond　inside　the　chain　segment.　The　hydrogenation　results　show　that　the　hydrogenation　activity　of　NBR　in　the　electron　donating　solvents　is　higher　than　that　in　weak　electrophilic　solvents,　but　no　matter　which　solvent　is　selected,　the　hydrogenation　selectivity　to　C=C　double　bonds　of　NBR　is　100%.　This　study　provides　a　theoretical　basis　for　the　selection　of　solvents　in　the　NBR　heterogeneous　solution　hydrogenation　system.　©　2021,　Editorial　Board　of　CIESC　Journal.　All　right　reserved.