The spliceosome is the core molecular machinery for RNA splicing, and its dysfunction can disrupt gene expression programs during neurodevelopment. With the widespread application of whole-genome sequencing, transcriptome sequencing, and long-read sequencing, the spectrum of spliceosome-related neurodevelopmental disorders has been continuously expanding. This review summarizes the genetic features, clinical phenotypes, and molecular mechanisms of pathogenic variants at three levels of the spliceosome: small nuclear RNAs, small nuclear ribonucleoproteins, and spliceosome assembly/regulatory factors. It further discusses tissue selectivity and phenotypic heterogeneity of spliceosome-related disorders, and highlights emerging research strategies and advances in RNA-targeted therapies, with the aim of informing mechanistic exploration and clinical research.