A method and a platform for detecting an immunogenicity of a tumor neoantigen are provided. Specifically, the detection method includes the following steps: culturing human peripheral blood monocytes ex vivo for 13 days, adding an antigenic peptide fragment of human influenza virus and stimulating and activating cytokines, antigenic peptides, and immunoadjuvants during the 13 days, and finally conducting enzyme-linked immunospot (ELISPOT) chromogenic reaction and instrument-based scanning, counting, and analysis to detect the immunogenicity of tumor neoantigen. An application of the detection method and platform in biomedicine is provided. Compared with the prior art, the detection method and platform have advantages and characteristics of a short detection period, high convenience, low consumption of experimental cells, and low detection cost. Therefore, the detection method and platform can be used for ex vivo high-throughput assay for the immunogenicity of the tumor neoantigen.