Based　on　the　particle　flow　theory　(PFT),　the　bonded　particle　model　(BPM)　and　the　smooth　joint　model　were　combined　into　a　grain-based　model,　aiming　to　reveal　the　micro　fracture　features　of　brittle　rock.　Then,　a　lattice　model　was　created　to　reproduce　the　mechanical　properties　of　the　rock,　and　the　samples　were　under　tensile　test　and　uniaxial/triaxial　compression　under　different　confining　pressures.　The　tests　were　conducted　to　examine　the　failure　mechanism　and　strength　features　of　the　rock.　Through　the　comparison　of　simulation　results　and　test　results,　the　grain-based　model　is　proved　applicable　and　reliable　in　the　study　of　mechanical　features　of　brittle　rock.　During　the　research,　the　grain-based　model　accurately　described　the　crack　features　of　brittle　rock　in　the　loading　process,　and　visually　reproduced　the　internal　crack　development　that　leads　to　brittle　rock　failure.　With　the　ability　to　simulate　brittle　material　failure　of　a　greater-Than-　10　compressive-Tensile　strength　ratio,　the　proposed　model　can　reveal　the　entire　deformation　and　failure　process　of　brittle　rock.