The invention provides an application of aurantiamide in preparing rheumatoid arthritis preventing drugs. The structural formula of aurantiamide is as shown in the specification. According to results of animal pharmacodynamic tests based on the aurantiamide, CIA(collagen-induced arthritis) severity and morbidity are suppressed obviously by the aurantiamide, and TNF-alpha (tumor necrosis factor-alpha), IL-17(interleukin-17) and IFN-gamma (interferon-gamma) of splenocyte supernate can be decreased, secretion of TNF-alpha, IL-17 and IFN-gamma of proinflammatory cytokine can be suppressed, and accordingly the CIA can be prevented and the aurantiamide can be applied to preparation of rheumatoid arthritis preventing drugs. Specifically, the drugs refer to pharmaceutical compositions which are prepared from the aurantiamide serving as an active ingredient and conventional pharmaceutical carriers, can be prepared into tablets, dispersible tablets, orally disintegrating tablets, sustained release tablets, capsules, soft capsules, drop pills, granules, injections, powder-injections, aerosol or the like, and has high clinical application value.