Abstract: The present invention relates to a combined treatment composition for tumor treatment and a combined treatment method. The combined treatment composition or a medicine kit comprises a therapeutically effective amount of a platinum chemotherapeutic drug, and a therapeutically effective amount of CpG oligonucleotide and a therapeutically effective amount of R848. The present invention further provides a combined treatment method for treating a tumor by means of the combined treatment composition or the medicine kit. Firstly, a low-dose chemotherapeutic drug is used to kill a tumor so as to release a tumor neoantigen, such that a body immune system autonomously identifies and screens the neoantigen, and then CpG oligonucleotide and an R848 activator of immune response are used to induce and promote the body to generate immune response specific to the tumor neoantigen, such that the anti-tumor function of T cells is improved and enhanced, thereby achieving the effect of inhibiting tumor growth.