Melanoma is the most lethal type of malignant tumor among skin cancers. The mechanism of its development and progression is complex, and it is highly invasive, metastatic and lethal, with a poor prognosis. Therefore, it is particularly important to strengthen the basic research on this disease. Single-cell transcriptome sequencing, a rapidly developing new technology in recent years, has greatly promoted the basic and clinical research of melanoma with its unique advantages, such as exploring the heterogeneity of cellular subpopulations, identifying rare cells, and using bioinformatics algorithms to reveal the differentiation trajectories of different tissue and cells. This article reviews the progress in single-cell transcriptome sequencing studies of melanoma in terms of tumor heterogeneity and tumor immunity.