The　wave　transmission　properties　in　double-scale　discontinuous　rock　masses　subjected　to　both　static　prestress　and　dynamic　loads　are　investigated.　The　double-scale　discontinuous　rock　masses　refer　to　rock　masses　that　contain　macrojoint　and　microdefect.　The　split　three　characteristic　lines　method　is　extended　to　predict　wave　propagation　under　combined　static-dynamic　loads　by　introducing　the　mechanical　properties　of　macrojoints　and　microdefects　under　static　prestress.　The　amplitude　and　energy　transmission　coefficients　of　wave　propagation　through　rock　masses　under　different　static　prestresses　are　investigated.　A　comparison　between　the　results　of　the　present　study　and　those　of　a　traditional　study　that　does　not　consider　microdefects　is　performed　to　evaluate　the　effect　of　microdefects　on　wave　propagation.　The　results　show　that　the　proposed　method　can　effectively　analyze　wave　propagation　through　double-scale　discontinuous　rock　masses　under　static　prestress.　The　amplitude　and　energy　transmission　coefficients　increase　with　an　increase　in　static　prestress.　Under　an　arbitrary　static　prestress,　the　results　obtained　from　the　present　study　are　always　smaller　than　those　obtained　from　the　traditional　study,　because　the　effects　of　microdefects　are　considered　in　the　present　study.　However,　when　the　static　prestress　is　small,　the　effect　of　microdefects　on　wave　propagation　is　slight.　When　the　static　prestress　is　large,　the　effect　of　microdefects　on　wave　propagation　is　relatively　significant,　and　microdefects　in　the　rock　mass　cannot　be　disregarded.