Based　on　a　dam　foundation　engineering　in　Fujuan　province,　single-hole　acoustic　test,　cross-hole　acoustic　test　and　seismic　wave　test　were　carried　out　to　detect　the　P-wave　velocity　of　dam　foundation　rock　mass　before　and　after　consolidation　grouting.　The　elastic　theory　was　used　to　calculate　dynamic　elastic　modulus;　and　the　change　of　deformation　parameters　before　and　after　consolidation　grouting　were　studied.　A　modified　Hoek-Brown　criterion　was　proposed　to　calculate　the　parameters　in　Hoek-Brown　criterion.　The　results　show　that　the　consolidation　grouting　effect　is　controlled　by　the　groutability　of　rock　mass　and　effected　by　the　rock　mass　structure.　The　consolidation　grouting　effects　in　different　directions　are　different.　For　strongly　weathered　rocks,　the　consolidation　grouting　effect　in　vertical　direction　is　better　than　that　in　horizontal　direction.　For　medium　weathered　rocks　with　gently　dipping　discontinuous　faces,　the　consolidation　grouting　effect　in　horizontal　direction　is　better　than　that　in　vertical　direction.　The　functional　relationship　between　the　increasing　rate　of　dynamic　elastic　modulus　and　the　increasing　rate　of　velocity　is　quadratic.　The　functional　relationship　between　the　increasing　rates　of　m,　s　(where　m　is　Hoek-Brown　parameter,　s　is　parameter　related　to　quality　of　rock　mass)　and　the　increasing　rate　of　velocity　for　strongly　weathered　rocks　are　both　linear　and　for　medium　weathered　rocks　are　both　cubic.　It　is　of　important　significance　for　design　and　construction　of　grouting.