Lignin-based　epoxy　resin　is　synthesized　by　a　phenolated　lignosulfonate,　which　comes　from　sodium　lignosulfonate　through　phenolated　reaction　with　HBr　and　tributhexadecylphosphonium　bromide　as　catalysts.　The　phenolated　lignosulfonate　is　epoxidized　by　epichlorohydrin　to　produce　lignin-based　epoxy　resin.　The　components　and　structure　of　phenolated　product　are　characterized　by　the　elemental　analysis,　Gel　permeation　chromatography　(GPC),　Fourier　transform　infrared　spectrometer　(FT-IR),　ultraviolet-visible　spectrometry　(UV),　and　1H-nuclear　magnetic　resonance　(1H-NMR).　Results　show　that　parts　of　the　methyloxygen　group　of　sodium　lignosulfonate　are　transformed　into　phenolic　hydroxy,　and　the　content　of　the　phenolic　hydroxy　group　of　phenolic　products　increases　2.6　times　than　that　of　sodium　lignosulfonate,　which　satisfies　the　requirement　of　prepared　lignin-based　epoxy　resin.