Positive anti-nRNP and SM antibodies are usually indicative of abnormal immune function and possible autoimmune diseases such as SLE and mixed connective tissue disease. Positive anti-nRNP antibodies are mainly seen in mixed connective tissue disease and are an important serologic basis for the diagnosis of mixed connective tissue disease. However, it can also be seen in other autoimmune diseases, such as systemic lupus erythematosus. If anti-nRNP antibodies are present in mixed connective tissue disease, they are often accompanied by joint pain and sclerosis of the extremities. Positive anti-SM antibody is closely related to SLE and is a marker antibody for clinical diagnosis of SLE. However, its positivity rate is low, i.e., those with positive anti-SM antibody are usually SLE, but those with negative anti-SM antibody cannot completely exclude SLE. Once autoimmune disease occurs, it is necessary to combine the clinical manifestations and signs, and further improve the relevant examinations under the guidance of the doctor, in order to clarify the diagnosis and active treatment. At the same time, it is necessary to pay attention to the regulation of emotions and maintain a relaxed mood. If autoantibodies are found to be abnormal, it is recommended to consult a doctor in a timely manner and follow the doctor’s instructions for standardized diagnosis and treatment.