Based　on　the　principle　of　fracture　mechanics,　this　paper　studies　the　mechanical　model　of　water-bearing　crack　development　in　deep　rock　mass　under　blasting　disturbance,　and　derives　the　expression　of　the　dynamic　and　static　coupling　strength　of　the　rock　mass.　In　the　meantime,　the　crack　initiation　and　propagation　of　tensile　shear　and　compressive　shear　cracks　were　investigated　to　disclose　the　effect　of　blasting　disturbance,　water　pressure,　geostress　and　crack　angle　on　crack　propagation,　and　to　obtain　the　formula　of　crack　propagation　length.　The　formula　was　implemented　in　a　case　study.　The　results　show　that,　in　tensile-shear　fracture,　the　geostress　accelerates　the　crack　propagation　in　the　same　direction;　in　compressive-shear　fracture,　the　crack　inclination　angle　of　the　position　most　vulnerable　to　compressive-shear　fracture　varies　with　the　internal　friction　angle　of　the　rock　mass;　the　blast　disturbance　load,　in　a　certain　sense,　elevates　the　water　pressure　in　the　cracks;　the　crack　propagation　length　decreases　in　a　near　linear　pattern　with　the　increase　in　the　distance　from　the　explosion　source.