During　the　numerical　simulation　of　blasting　in　jointed　rock　masses,　the　accuracy　of　joint　geometric　parameters　is　one　of　the　key　factors　affecting　the　numerical　results.　To　facilitate　the　numerical　simulation,　most　of　the　previous　studies　on　blasting　in　jointed　rock　masses　were　conducted　on　regular　jointed　rocks,　which　is　not　conducive　to　fully　revealing　the　dynamic　responses　and　blast-induced　damage　characteristics　of　jointed　rock　mass.　In　this　study,　scanline　sampling　and　borehole　sampling　were　employed　to　obtain　the　surface　and　internal　joint　structures　of　the　rock　bench.　To　represent　the　joint　geometry,　a　reconstruction　technique　for　threedimensional　(3D)　jointed　rock　masses　in　LS-DYNA　was　proposed　utilizing　MATLAB　code.　In　the　process,　the　elements　on　joint　surfaces　were　identified　and　assigned　mechanical　parameters　of　joints　to　construct　the　3D　jointed　rock　model,　where　the　geometrical　properties　of　generated　joints　obey　the　statistical　distribution　obtained　from　the　scanline　survey.　Taking　an　open-pit　limestone　mine　as　an　example,　a　statistical　analysis　of　the　3D　distribution　of　joints　was　carried　out　and　used　to　construct　a　3D　jointed　rock　numerical　model　for　bench　blasting.　Comparisons　between　the　bench　slope　extracted　from　the　numerical　model　and　the　actual　joint　trace　mapping　from　a　rock　exposure　are　performed,　and　the　similarity　between　the　two　contour　plots　of　joint　orientations　reaches　91.6　%.　For　comparison　tests,　the　bench　blasting　was　simulated　by　an　intact　rock　model　and　the　jointed　rock　model.　The　results　indicate　that　the　dynamic　responses　and　blastinduced　damage　characteristics　of　jointed　rocks　are　significantly　affected　by　the　geometry　of　joints.　Compared　with　the　intact　rock　model,　the　presence　of　joints　causes　stress　concentration　and　local　strengthening　of　rock　damage　between　adjacent　joints,　which　results　in　a　30.5　%　increase　in　the　damage　volume.　Furthermore,　a　field　blasting　test　was　conducted　to　analyze　the　accuracy　of　the　jointed　rock　model.　The　results　show　that　the　fragment　size　distributions　obtained　from　the　jointed　rock　numerical　model　and　the　filed　test　are　generally　consistent,　and　the　error　between　them　in　the　proportion　of　rock　fragments　with　a　size　of　0　similar　to　100　mm　is　only　12.8　%.　These　findings　indicate　that　the　proposed　reconstruction　method　of　the　jointed　rock　model　is　considerably　robust　for　characterizing　the　joint　geometry　of　in　situ　rock　masses　and　simulating　the　bench　blasting　in　jointed　rock　masses.