The　joint　planes　in　fractured　rock　mass　will　reduce　the　tensile　strength　and　shear　strength　of　rock　mass,　which　has　a　decisive　influence　on　the　deformation　and　failure　mode　of　engineering　rock　mass.　Furthermore,　infill　also　exists　between　the　joint　surfaces,　which　will　also　affect　the　shear　characteristics　of　the　joint.　A　method　of　importing　standard　joint　profile　into　PFC2D　was　proposed,　and　a　series　of　numerical　simulation　tests　were　carried　out　to　study　the　effect　of　joint　roughness　and　infill　thickness　on　the　shear　characteristics　of　joints.　The　numerical　results　revealed　that　rock　bolts　profoundly　improved　the　shear　strength　of　the　infilled　rock　joints,　enhanced　the　toughness　of　the　joint　surface,　increased　the　number　of　micro-cracks,　and　made　the　dilatation　more　obvious.　The　shear　stress　and　the　normal　displacement　of　unbolted　or　bolted　infilled　rock　joints　increased　with　increasing　the　joint　roughness　and　decreasing　the　infill　thickness.　The　maximum　horizontal　compression　stress　in　the　middle　of　the　bolt　gradually　increased　with　the　increase　of　joint　roughness　coefficient.　Different　roughness　has　different　effects　on　the　number　of　micro-cracks　in　the　sample.　The　number　of　total　cracks　and　tensile　cracks　of　the　bolted　and　unbolted　specimens　increased　with　the　increase　of　joint　roughness　coefficient,　while　the　shear　cracks　remained　almost　the　same.　Through　the　study　of　the　coupling　effect　of　joint　roughness　and　infill　thickness　on　peak　shear　stress,　results　can　be　obtained　as　follows.　The　unbolted　samples　are　highly　sensitive　to　JRC　changes.　The　greater　the　infill　thickness,　the　greater　the　sensitivity　of　unbolted　samples　to　JRC　changes.　The　reinforcement　effect　of　the　bolt　will　strengthen　the　meshing　strength　between　the　joint　surface　and　the　filling　material;　that　is,　the　meshing　strength　is　positively　correlated　with　joint　roughness　and　negatively　correlated　with　filling　thickness.