Rotary-percussion　drilling　technology　was　used　to　improve　drilling　efficiency　in　marine　deep　hard　rock　formations,　but　the　compatibility　among　the　engineering　&　tool　parameters,　PDC　cutter,　and　the　hard　rock　formation　has　not　been　sufficiently　studied.　In　response,　a　theoretical　model　of　the　axial　impact　hammer　motion　mechanism　under　drilling　fluid　driving　conditions　was　established,　and　the　speed　and　frequency　of　reciprocating　motion　of　the　hammer　were　analyzed　under　different　drilling　fluid　and　tool　structure　parameters.　A　numerical　model　of　stress　waves　generated　by　the　axial　impact　hammer　on　the　base　was　established,　and　the　variation　of　stress　wave　parameters　(peak　value,　duration,　etc.)　with　impact　velocity　was　analyzed.　Based　on　the　calculation　mentioned　above,　a　numerical　model　of　PDC　drilling　teeth　cutting　hard　rock　formations　under　the　coupling　effect　of　dynamic　and　static　loads　during　rotary-percussion　drilling　was　established,　and　the　changes　in　penetration　depth,　rock　damage,　and　rock　debris　size　under　different　engineering　and　tool　parameter　conditions　were　analyzed.　The　research　results　indicated　that　as　the　drilling　fluid　displacement　and　density　increased,　the　impact　velocity　and　reciprocating　frequency　presented　linear　and　nonlinear　growth　trends,　respectively,　which　was　beneficial　for　increasing　the　penetration　depth,　but　it　would　increase　the　size　of　rock　debris.　The　impact　velocity　and　reciprocating　frequency　exhibited　a　nonlinear　decreasing　trend　as　the　nozzle　diameter　increased,　leading　to　decreased　penetration　depth　and　reduced　size　of　rock　debris.　As　the　diameter　of　the　pressure-bearing　ring　increased,　the　penetration　depth　increased　initially　and　subsequently　reduced.　The　findings　could　offer　a　reference　for　the　engineering　and　tool　parameter　optimization　during　rotary-percussion　drilling.