Mixed connective tissue disease is a clinical syndrome in which the serum contains high titers of speckled antinuclear and anti-U1RNP antibodies, with a combination of symptoms of various diseases such as systemic lupus erythematosus, systemic sclerosis, polymyositis/dermatomyositis, and rheumatoid arthritis. After the onset of mixed connective tissue disease, the joint tissues, skin, heart, lungs, kidneys, and other tissues and organs of the body may have different degrees of lesions and damage, and the patient may have fever, dyspnea, joint pain, and other abnormal symptoms, and the joint tissues may have stiffness and swelling, deformities, and other abnormal pathological manifestations. Mixed connective tissue disease can cause serious damage to the body, for this condition can be prescribed to use prednisone acetate, cyclophosphamide and other drugs for comprehensive treatment, can make the condition get stable control. It is recommended that patients with mixed connective tissue disease consult the rheumatology and immunology department in a timely manner, and follow the doctor’s instructions to actively treat the disease, and usually need to pay attention to a light diet and actively prevent infections, as well as regular review.