The preparation method of radiation-sensitive copolymer carrier for coating radiated nanoparticles and/or chemotherapy drugs includes forming a nanosphere by diselenide block copolymers and DSPE-PEG-biomarkers to coat chemotherapy drugs and/or radiated nanoparticles that can be released from the opened nanosphere by protons penetrating tissue during proton therapy. The treatment effect of proton therapy is enhanced by two ways of using the radiated nanoparticles released from an opened nanosphere to produce nuclear fission with the protons for releasing electrons to destroy cancer cells of tumor and the chemotherapy drugs released from the opened nanosphere for distributing among tissue to kill the cancer cells of the tumor.