Tumor hypoxia, as a hallmark of most solid tumors, poses a serious impediment to O2-dependent anticancer therapies, such as photodynamic therapy (PDT). Although utilizing nanocarriers to load and transport O2to tumor tissues has been proved effective, the therapeutic outcomes have been impeded by the low O2capacity and limited tumor penetration of the nanocarriers. To address these problems, we incorporated perfluorooctyl moieties into nanocarriers to improve the encapsulation of perfluorooctyl bromide viafluorophilic interactions, leading to elevated O2capacity of the nanocarriers. Meanwhile, to enhance the tumor cell penetrating ability as well as reduce reticuloendothelial system recognition, the nanocarrier was further decorated with a cell-penetrating peptide, which was masked with a protecting group viaan acid-labile amide bond for prolonged circulation time and acid-activated cell penetration. The in vitrostudy demonstrated that, apart from remarkably boosting the photocytoxicity of chlorin 6 (Ce6) at a low dosage, the rationally designed O2@DANPCe6+PFOBcould even alleviate the pre-existing tumor hypoxia. After intravenous injection, O2@DANPCe6+PFOBexhibited significant tumor accumulation and retention, and potent tumor growth inhibition compared to traditional PDT. Overall, the O2@DANPCe6+PFOBmediated O2self-supplemented PDT with tumor acidic microenviornment-activated cell penetration provides a promising strategy in anticancer treatment.