Photodynamic　immunotherapy　(PIT)　has　emerged　as　a　promising　approach　for　efficient　eradication　of　primary　tumors　and　inhibition　of　tumor　metastasis.　However,　most　of　photosensitizers　(PSs)　for　PIT　exhibit　notable　oxygen　dependence.　Herein,　a　concept　emphasizing　on　transition　from　molecular　PSs　into　semiconductor-like　photocatalysts　is　proposed,　which　converts　the　PSs　from　type　II　photoreaction　to　efficient　type　I　photoreaction.　Detailed　mechanism　studies　reveal　that　the　nanostructured　phthalocyanine　aggregate　(NanoNMe)　generates　radical　ion　pairs　through　a　photoinduced　symmetry　breaking　charge　separation　process,　achieving　charge　separation　through　a　self-substrate　approach　and　leading　to　exceptional　photocatalytic　charge　transfer　activity.　Additionally,　a　reformed　phthalocyanine　aggregate　(NanoNMO)　is　fabricated　to　improve　the　stability　in　physiological　environments.　NanoNMO　showcases　significant　photocytotoxicities　under　both　normoxic　and　hypoxic　conditions　and　exhibits　remarkable　tumor　targeting　ability.　Notably,　the　NanoNMO-based　photodynamic　therapy　and　PD-1　checkpoint　inhibitor-based　immunotherapy　synergistically　triggers　the　infiltration　of　cytotoxic　T　lymphocytes　into　the　tumor　sites　of　female　mice,　leading　to　the　effective　inhibition　of　breast　tumor　growth.　©　The　Author(s)　2025.