Abstract: Long non-coding RNAs (lncRNAs) are RNA molecules constituted by more than 200 nucleotides, exhibiting relatively low sequence conservation. For a long time, they had been regarded as "transcriptional noise”, that is, non-functional RNA molecules, in the biological field. However, in recent years, as research has advanced, scientists have unveiled numerous small open reading frames (sORFs) within lncRNAs, some of which can encode micropeptides. These micropeptides have been confirmed to participate in various cellular processes and gene expression regulatory networks, playing crucial roles. This discovery has opened new research directions for further exploration of life activities and clinical diagnosis and treatments of diseases. This review summarizes the roles of lncRNA-encoded micropeptides in pathological and physiological processes, the subcellular localization and functional mechanisms of micropeptides, and the progress in micropeptide research methodologies, aiming to provide insights and references for the development of novel integrated micropeptide-based diagnostics and therapeutics.