Weakly positive anti-Jo-1 antibodies refer to laboratory tests that show weakly positive autoantibodies, indicating that a lesion has developed, but the test results are weakly positive because the condition is not particularly severe. Most of these cases are associated with polymyositis. Antibodies for polymyositis include myositis-specific antibodies and myositis-associated antibodies. Increased positivity of Jo-1 antibody is representative of the test and can be used as an early diagnosis of polymyositis. However, it also needs to be judged in combination with imaging tests, such as muscle MRI, chest CT, cardiac ultrasound, electrocardiogram, etc., as well as in combination with pathological tests to confirm the diagnosis. Polymyositis is an autoimmune disease characterized by muscle weakness and muscle pain, often caused by autoimmune dysfunction, which can lead to symmetrical muscle weakness in the proximal limbs and throat. It needs to take timely targeted treatment measures to improve, in order to make the condition effectively controlled, but also to slow down the development of the disease.