Heterogeneous nuclear ribonucleoproteins (hnRNPs) are a family of multifunctional RNA-binding proteins that bind to nascent transcripts synthesized by RNA polymerase II and participate in the regulation of transcript stabilization and maturation in the form of complexes. hnRNP A1 is an important member of this protein family and is not only widely involved in the regulation of alternative splicing of genes related to cancer and neurological diseases, but also plays an important role in viral infection, cellular aging and stress recovery. Besides, as hnRNP A1 is a typical RNA-specific binding protein, the rules of identifying specific sequences through dynamic three-dimensional structures have also been revealed in the regulation of transcription and alternative splicing. This review summarizes the research progress of hnRNP A1 in recent years, providing references for the further exploring its function in disease development.