Limonoids are a group of secondary metabolism containing furan ring and highly oxidized tetracyclic triterpene, with significant anticancer, antiviral, antioxidant, antimicrobial, insect antifeedant, antiinflammatory and analgesic atherosclerosis and other biological activities. Limonoids are mainly found in Rutaceae and Meliaceae families, and which are particularly abundant in the citrus seeds. The research on the species, structure and biosynthetic pathways of limonoids in citrus seeds and the research progress on the bioactivity of limonin and its analogues in recent years are discussed in this paper, and its application in the food industry, agriculture, medicine and animal husbandry are also reviewed, in order to provide reference for the application of limonin and its analogues in citrus seeds.