The　parameters　calibration　of　the　original　fracture　constitutive　model　for　the　joint　element　in　the　finite-discrete　element　method　(FDEM)　is　very　complex.　To　simplify　the　parameter　calibration　procedure,　we　firstly　propose　a　linear　fracture　constitutive　model　for　the　two-dimensional　finite-discrete　element　method　(FDEM).　Based　on　the　simplified　constitutive　model　for　the　joint　element,　the　proposed　calibration　procedure　only　involves　adjusting　two　parameters　(ro　and　rs),　which　represent　the　post-peak　strain　to　pre-peak　strain　ratio　and　have　a　clear　physical　meaning.　Other　rock　mechanical　parameters　can　directly　take　from　the　experimental　values.　Then,　the　correctness　of　the　proposed　fracture　constitutive　model　is　verified　by　a　series　of　rock　numerical　tests.　Finally,　the　calibration　procedure　of　the　input　parameters　for　the　Jinping　Baishan　Group　marble　is　provided　by　using　the　linear　fracture　constitutive　model.　The　proposed　constitutive　model　can　significantly　simplify　the　parameter　calibration　process　and　improve　the　computational　efficiency,　which　enables　FDEM　better　applied　to　practical　engineering.