Abstract: A high-efficiency anti-tumor nano-drug delivery system containing hydralazine (hydralazine-nanoparticles abbreviated as H-NPs) is provided. The drug delivery system takes hydralazine and doxorubicin combined by a ?-? bond as a hydrophobic core and takes dextran as a hydrophilic shell. The high-effective anti-tumor nano-drug delivery system containing hydralazine can increase the vascular permeability and blood perfusion of the tumor site, improve the enrichment and penetration of nanoparticles in the tumor, reduce tumor hypoxia, increase the sensitivity of the tumor to a chemotherapy drug doxorubicin, and significantly improve its anti-tumor effect by expanding the tumor blood vessels and regulating tumor microenvironment (TME).