Giant cell arteritis (GCA) is an autoimmune vasculitis involving large and medium arteries, but the relationship with other autoimmune diseases is unclear. We reported a case of an 85-year-old woman who was diagnosed with GCA, Sjögren’s syndrome (SS) and rheumatoid arthritis (RA) simultaneously, and discussed the potential link between these diseases.  The anti-nuclear antibody (ANA) and anti-centromere antibody (ACA) was positive in serum. Color Doppler ultrasound of temporal arteries showed thickening and hardening of bilateral temporal artery wall with varying width and narrowness of lumen. She was diagnosed with GCA, SS, and RA. At the same time, she was given antiinflammatory treatment with methylprednisolone, hydroxychloroquine and tripterygium glycosides. Her condition was controlled; the mental state and inflammatory biomarkers were significantly improved (CRP < 0.5 mg/L, ESR 13.6 mm/h). She was discharged from the hospital and outpatient review regularly. GCA, SS, and RA can occur simultaneously or continuously, but were rare. The combination of CRP and ESR improved the specificity and positive rate of GCA diagnosis. We speculated that there might be common pathogenic factors involved in GCA, RA and SS through the analysis of this case. Through the analysis of this case, we speculated that there may be a common virulence factor involved in GCA, RA and SS. Further exploration is needed in the future to elucidate their relationship and provide more support for early diagnosis and treatment.