Peritoneal carcinomatosis is a common manifestation of advanced malignant tumors. Its complex pathological features and unique immunosuppressive microenvironment limit the effectiveness of traditional treatment. At present, immunotherapy for peritoneal carcinomatosis shows certain potential, but still faces many challenges. Future research should focus on the development of new immunotherapy targets, the combination of local and systemic drug delivery approaches, the characterization of the tumor microenvironment using single-cell genomics and spatial transcriptome technologies, and the screening of appropriate populations using artificial intelligence, which is expected to effectively improve patient survival.