The invention belongs to the technical field of pharmaceutical chemistry and medicine, relates to a novel tumor necrosis factor (TNF-alpha) inhibitor and particularly relates to a small molecule 3-aryl-1-indanone derivative TNF-alpha inhibitor and its medicinal use. The invention provides the 3-substituted-1-indanone derivative compound shown in the following formula (1). An in-vitro experiment result shows that the prepared derivative compound has specific inhibition effects on a tumor necrosis factor (TNF-alpha) produced by LPS-stimulated macrophages RAW 264.7. The derivative can be used for preparation of a small molecule treatment drug for treating ulcerative colitis and as a small molecule TNF-alpha inhibitor and can be used for treating human TNF-alpha increasing-mediated immunoinflammatory diseases such as ulcerative colitis, Crohn's disease, rheumatoid arthritis, osteoarthritis and psoriasis.