Uveal melanoma (UM) is the most common intraocular malignancy in adults. The prognosis is poor once metastasis has developed. The treatment of metastatic UM remains challenging nowadays due to lacking a deep understanding of the biological characteristics of this disease. Here, we revealed the cell subpopulations with distinct functional status and the existence of cells with high invasive potential within heterogeneous primary and metastatic UM. The single-cell sequencing data were retrieved from GSE139829 and GSE138433, through which we identified a new cell cluster related to metastatic UM as a unique type of immune cell. The cell-cell communication was conducted by 'Cellchat' to understand the cell crosstalk between these immune cells and their surrounding cells. The crucial signals contributing most to outgoing or incoming signaling of this cell group were identified to reveal the crucial pathway genes. Furthermore, we judged the prognostic value of these candidates on the basis of the data downloaded from The Cancer Genome Atlas. The results demonstrated that the increased IL10, SELPLG, EPHB and ITGB2 signaling pathways could be promising predicting factors for the patient prognosis in UM. Conclusively, we discover the potential key signals of UM for occurrence and metastasis, and also provide a theoretical basis for judging whether there is a high risk of metastasis or recurrence.