Inflammatory bowel disease (IBD), including Crohn's disease (CD) and ulcerative colitis (UC), represents a chronic and recurrent inflammatory ailment of the intestines. It strikes a harsh blow to patients' quality of life. Currently, there is a dearth of effective treatments for IBD, which causes patients to endure significant distress. Thus, it is of utmost urgency to formulate a treatment plan for IBD that is safe, effective, and affordable. In recent years, natural products have increasingly become a new strategy to alleviate IBD due to their safety and effectiveness. Among many natural products, microalgae have attracted extensive attention from researchers, owing to their abundance in a diverse range of bioactive constituents, such as polysaccharides, phycocyanin, and carotenoids. Microalgae and the bioactive compounds within them can effectively alleviate IBD. Their potential application value is discussed as they are expected to be new strategies concerning the prevention and treatment of this disease. In retrospect, we start from the pathogenesis of IBD, and combining with the deep therapeutic mechanism of microalgae-derived active ingredients, this article expounds on its broad prospects in the treatment of IBD. Meanwhile, the positive effects of microalgae as biological carriers and symbiotic components on the treatment of IBD were summarized.