To explore the current status and progress of immunotherapy for colorectal cancer (CRC), with “Colorectal Cancer”, “Immunotherapy”, and corresponding MeSH terms for various therapeutic modalities as core search keywords to retrieve literature published between 2015 and 2025 from databases including PubMed, with relevant studies on immune checkpoint inhibitors (ICIs), adoptive cell transfer (ACT), and tumor vaccines included for screening. Finally, 51 studies meeting the criteria were selected to comprehensively evaluate the efficacy, safety, and factors influencing the therapeutic effects of the aforementioned immunotherapeutic approaches. The results showed that ICIs exhibited significant efficacy in immunotherapy for patients with microsatellite instability-high/deficient mismatch repair (MSI-H/dMMR) metastatic CRC or those undergoing neoadjuvant therapy for CRC, while their therapeutic effect was limited in patients with microsatellite stability/proficient mismatch repair (MSS/pMMR) CRC, and the combined application of ICIs with chemotherapy, radiotherapy, or targeted therapy is expected to become a breakthrough direction for immunotherapy in MSS/pMMR CRC patients. Tumor vaccines demonstrated a certain ability to stimulate the body’s immune response but had not yet achieved the desired clinical efficacy. ACT showed promising prospects in preliminary studies yet required further optimization in terms of technology and safety. Additionally, various factors such as the tumor microenvironment and gene mutation status had significant impact on the efficacy of immunotherapy, and the rational combination of immunotherapy with other treatment methods may enhance its therapeutic effect. Currently, certain achievements have been made in CRC immunotherapy and therapeutic modalities are continuously developing, but in-depth research on therapeutic mechanisms, screening of populations with potential benefits, and optimization of treatment regimens is still necessary to promote CRC immunotherapy to a new stage and bring greater benefits to patients.