Extraocular muscle weakness is a disorder of extraocular muscle movement due to various factors, muscle weakness, commonly seen in sarcoidosis, pediatric myasthenia gravis, progressive myotonic dystrophy, etc. There is a certain deficiency of qi and blood and lack of vitamins causing the problem. There may also be a relationship with loss of tendon support, lack of sleep, and congenital defects. Tests needed for extraocular muscle weakness: 1. Blood, urine and cerebrospinal fluid routine tests are normal. Departmental x-ray can be seen in 15% of MG patients, especially those older than 40 years old with thymoma, and chest CT can detect all thymomas except microadenoma. 2.Thyroid function measurement can be performed for suspected MG. 3.Serum autoantibody profile test. 4.Muscle fatigue test. 5.Anti-cholinesterase drug Tensilon test and neostigmine test have the same diagnostic value and are used for MG diagnosis and identification of various types of crisis. 6, electromyography low frequency (1-5Hz) repetitive nerve electrical stimulation is a commonly used neuromuscular conduction physiological examination, is the most common method to detect NMJ disease. 2-3Hz low frequency repetitive electrical stimulation of peripheral nerves causes a rapid decrease in the action potential of innervated muscles, due to local Ach depletion in NMJs, resulting in a decrease in EPPs.