 This study proposes a novel platinum nanosyme, point NP, loaded reactive oxygen species, ROS, responsive prodrug nanoparticle, CPTTKHPPH slash point NP, which can efficiently catalyze the decomposition of hydrogen peroxide, H2O2, into oxygen to relieve hypoxia and enhance photodynamic therapy, PDT. This point NP-based prodrug nanoparticle can also be used as a tumor diagnosis agent due to its desirable long circulation and enhanced in vivo targeting. In vitro and in vivo studies show that this prodrug nanoparticle can effectively inhibit tumor proliferation and growth. Therefore, it can serve as a new cancer theranostic agent and further promote the research of chemo-photodynamic synergistic cancer therapy. This article was authored by Enghao, Yuan Chen, Xilong He, and others.