RNA splicing, a critical process in eukaryotic gene expression, plays a fundamental role in the regulation of gene expression by removing introns from precursor mRNA and joining exons. This process is primarily mediated by the spliceosome complex, while the assembly and activation of the spliceosome predominantly rely on splicing factors, facilitating the two-step transesterification. The splicing factor 3B subunit 1 (SF3B1) occupies a crucial position within the U2 RNP that constitutes the spliceosome complex. Alternations in the phosphorylation level of SF3B1 affect the cellular splicing process, subsequently influencing normal cell function, as well as the proliferation and migration of tumor cells. This article summarizes the research to date on SF3B1 within the context of phosphoproteomics, with particular emphasis on the role of SF3B1 in splicing and the impact of phosphorylation modifications on SF3B1.