Induction　of　antigen-specific　immune　response　by　maturing　dendritic　cells　(DCs)　is　a　promising　strategy　for　anti-tumor　immunotherapy.　However,　the　immunosuppressive　tumor　microenvironment　(TME)　and　the　ineffective　tumor-associated　antigen　(TAAs)　presentation　of　DCs　have　hindered　the　efficacy　of　immunotherapy.　Herein,　we　developed　an　immunostimulatory　nanosphere　by　direct　self-assembly　of　cyanine5　labeled　CPG　oligodeoxynucleotide　and　doxorubicin　(Cy5-CPG/DOX).　The　introduction　of　Cy5　into　CPG　could　increase　the　interaction　of　Cy5-CPG　and　DOX,　accelerating　the　formation　of　Cy5-CPG/　DOX　nanosphere.　In　vivo,　DOX　can　effectively　downregulate　the　level　of　regulatory　T　cells　to　reverse　and　abrogate　immunosuppressive.　Meanwhile,　DOX　induce　immunogenic　cell　death　to　produce　TAAs,　which　combined　with　Cy5-CPG　promote　the　maturation　of　DCs,　improving　the　TAAs　presentation　ability　of　DCs.　Thus,　the　Cy5-CPG/DOX　could　awaken　the　innate　immune　system,　sensitizing　tumors　to　immune　checkpoint　inhibitors　mediated　by　the　programmed　death-ligand　1　(PD-L1)　antibody.　In　this　way,　the　Cy5-CPG/DOX　combined　with　PD-L1　can　decrease　the　exhaustion　of　cytotoxic　T　lymphocytes,　eliciting　a　durable　systemic　anti-tumor　immunity　to　eradicate　cancer.　Our　work　establishes　a　stable　approach　for　constructing　immunostimulatory　nanodrug,　promoting　the　development　of　progressive　therapeutic　systems.(c)　2022　The　Author(s).　Published　by　Elsevier　Ltd.　This　is　an　open　access　article　under　the　CC　BY　license　(http://creativecommons.org/licenses/by/4.0/).