Lysine specific demethylase1 (LSD1) is a flavin adenine dinucleotide (FAD)-dependent monoamine oxidase. Studies have confirmed that aberrant expression of LSD1 is closely related to tumor metastasis and proliferation, and is currently one of the important targets for tumor-targeted therapy. In addition, LSD1 is involved in the development of various conditions such as neurodegenerative diseases, cardiovascular diseases, and inflammatory responses. Currently, several inhibitors have been developed for the clinical research stage. In this paper, the structure and mechanism of action of LSD1 and the research progress of LSD1 inhibitors are briefly introduced to provide some reference for the design and development of novel LSD1 inhibitors.