The　development　of　quantum　computing　has　attracted　considerable　attention　to　quantum　programming.　However,　debugging　quantum　programs　remains　a　complex　challenge.　Due　to　the　arbitrary　quantum　state　not　being　cloned　perfectly　and　the　observation　of　the　quantum　will　lead　to　the　state’s　collapse,　we　cannot　debug　quantum　programs　like　classical　environments.　This　study　introduces　QDebug,　a　novel　quantum　debugging　scheme　that　leverages　probabilistic　quantum　cloning　to　set　breakpoints　and　inspect　variables　in　quantum　programs.　By　probabilistic　cloning　a　qubit　within　a　quantum　program　and　measuring　the　duplicate,　QDebug　enables　indirect　observation　of　the　qubit’s　state　when　the　program　halts　at　a　breakpoint　and　does　not　affect　the　normal　execution　of　quantum　programs.　We　provide　a　theoretical　analysis　of　QDebug’s　feasibility　and　demonstrate　its　effectiveness　through　applications　in　quantum　programs.　©　2025　Science　Press.　All　rights　reserved.