The　degree　of　blending　(DOB),　which　is　controlled　by　the　diffusion　between　virgin　and　aged/rejuvenated　asphalt　binder,　has　a　major　impact　on　the　performance　of　the　asphalt　mixture　incorporated　with　reclaimed　asphalt　pavement　(RAP).　Despite　numerous　studies　investigating　the　DOB　through　experimental　methods,　the　blending　efficiency　of　warm　mix　asphalt　(WMA)　and　synchronous　rejuvenated　SBS-modified　asphalt　(SBSMA)　is　still　unexplored.　In　this　study,　a　dynamic　shear　rheometer　(DSR)　testing　approach　was　developed　to　quantify　the　blending　efficiency　of　WMA　modified　SBSMA　and　synchronous　rejuvenated　SBSMA.　The　novelty　of　this　approach　lies　in　the　innovative　use　of　a　DSR　asphalt　double-layer　structure　to　determine　the　DOB　in　combination　with　a　developed　theoretical　calculation　framework.　The　individual　and　synergistic　effects　of　WMA　additive　and　rejuvenator　type　on　the　DOB　of　WMA　modified　SBSMA-Synchronous　rejuvenated　SBSMA　were　investigated,　while　the　influence　of　blending　temperature,　blending　time,　and　dosage　of　aged/rejuvenated　SBSMA　on　the　blending　efficiency　were　systemically　evaluated.　Results　indicated　that　the　SBS　repairing　agent　in　the　synchronous　rejuvenator　can　dramatically　increase　the　DOB,　while　the　presence　of　WMA　additive　can　further　increase　the　DOB　by　improving　the　fluidity　of　the　virgin　SBSMA.　Furthermore,　increasing　the　blending　temperature/　blending　time　and　decreasing　the　dosage　of　aged/rejuvenated　SBSMA　were　also　conducive　to　enhancing　the　DOB.　In　addition,　a　blending　chart　of　the　WMA　modified　SBSMA-Synchronous　rejuvenated　SBSMA　was　developed　to　facilitate　the　accurate　prediction　of　the　DOB　at　any　given　blending　temperature　and　blending　time.