Multiple sclerosis (MS) is a chronic inflammatory demyelinating disease of the central nervous system (CNS). There is currently no satisfactory treatment for this disease. Pin1 is the only known peptidyl-prolyl cis/trans isomerase (PPIase) that is involved in many cellular processes, including immune responses. Numerous studies have shown that juglone effectively inhibits Pin1 activity. However, the effect of Pin1 inhibitor juglone on autoimmune diseases such as multiple sclerosis (MS) and its animal model, experimental autoimmune encephalomyelitis (EAE), remain incomplete. So the present study aimed to explore the therapeutic effects of the Pin1 inhibitor juglone on EAE. EAE was induced in C57BL/6 mice with myelin oligodendrocyte glycoprotein (MOG) and treatment with juglone. The health status of EAE was observed and inflammation explored using pathological analysis. The impact of juglone on immune cells was further examined using intracellular staining and flow cytometry. The results demonstrated that juglone ameliorates EAE and reduces inflammation and demyelination in the CNS. The study also found that juglone suppresses pathogenic Th1 and Th17 cells and the expression of CD83 and MHCII on dendritic cells in EAE. In addition, juglone ameliorates EAE. Pin1 inhibitors therefore hold great promise for autoimmune disease and MS therapy.