Abstract: Casein kinase 2-interacting protein-1 (CKIP-1) is a multifunctional scaffold protein with a pleckstrin homology domain. Its dynamic subcellular localization enables dual roles in tumor progression, “promoting” or “suppressing” malignancy by regulating immune metabolism and signaling networks within the tumor immune microenvironment (TIME). This review synthesizes current knowledge on CKIP-1’s structural characteristics and TIME regulatory mechanisms. We highlight that CKIP-1 inhibits macrophage M2 polarization, antagonizes Smurf1-mediated oncoprotein ubiquitination, and modulates key pathways, including TGF-β and PI3K/AKT. Targeting CKIP-1 enhances the efficacy of immune checkpoint inhibitors and CAR-T therapy, but clinical translation faces challenges, such as unclear tissue-specific mechanisms and combination toxicity. This review aims to synthesize the regulatory functions of CKIP-1 in the tumor immune microenvironment, thereby offering a theoretical basis for precision immunotherapy targeting CKIP-1 and further analyzing its dynamic mechanisms to advance clinical applications.