Myasthenia gravis is a state of severe respiratory distress in which the respiratory muscles of the medulla oblongata are severely affected by the rapid progression of the disease for various reasons, so that normal ventilation cannot be maintained and tetraplegia can occur. When the diagnosis of myasthenia gravis is established, the diagnosis of myasthenia gravis is based on the dose and duration of cholinesterase inhibitors applied in the past and the presence or absence of muscarinic symptoms. If it is still difficult to identify the crisis, Tensilon or neostigmine test should be done to identify the myasthenia gravis crisis, cholinergic crisis or antalgic crisis. 2, cholinesterase inhibitor application of the three types of crisis, muscle weakness crisis is the most common, when the diagnosis of muscle weakness crisis is clear, or when the type of crisis is difficult to clarify, neostigmine and atropine should be given immediately for inotropic treatment, and if necessary, another injection can be given in 20-30 minutes. However, cholinesterase inhibitors can increase airway secretions and thus may lead to exacerbation, the use of such drugs confuses the evaluation of the efficacy of other therapeutic measures, and overdose may lead to exacerbation, and this class of drugs does not change the course of myasthenia gravis crisis, but only relieves the symptoms of myasthenia gravis. 3, if necessary, the use of dry-run therapy if the application of high-dose cholinesterase inhibitors still can not relieve the crisis, as well as cholinergic crisis and rebound crisis patients, can be tracheotomy assisted breathing to ensure the use of “dry-run therapy”, discontinue the use of cholinesterase inhibitors for 72 hours, and later cholinesterase inhibitors from a small dose of drugs. This type of dry-run therapy often results in better outcomes. In this case, polarizing solution can also be applied, which can restore the function of motor end plate and thus normalize the function of acetylcholine-cholinesterase system. 4, mechanical ventilation for myasthenia gravis crisis can involve both respiratory muscles and upper airway muscles. The involvement of respiratory muscles can be as high as 99%, and the involvement of upper airway muscles can be more than 90%, so it is especially important to evaluate the function of respiratory muscles and upper airway muscles for patients with myasthenia gravis at an early stage. Mechanical ventilation is the most effective means of treating myasthenia gravis crisis, and some studies have shown that early mechanical ventilation can relieve respiratory distress, correct hypoxemia and hypercapnia, and shorten the duration of mechanical ventilation, while failure to timely mechanical ventilation may increase the risk of death. 5, timely on the nasal feeding tube to ensure the supply of drugs and nutrition patients with critical signs often have swallowing difficulties, many patients due to swallowing difficulties caused by lung infection and ventricular rest induced critical signs. Timely nasal feeding tube can ensure the application of cholinesterase inhibitor, nutrition and water supply, and also reduce the foreign body into the respiratory tract and reduce or alleviate the lung infection. 6, the application of adrenocorticotropic hormone in the conditions of assisted breathing, can be used hormone high-dose shock therapy. Such as methylprednisolone 1000 mg intravenous drip. If the condition of assisted breathing is not available, high-dose hormone shock therapy can not relieve the crisis but also aggravate the symptoms of muscle weakness, which should be alarmed. It can be induced by small doses of hormone, gradually increase the dose, and apply the corresponding antibiotics at the same time to prevent the spread of pulmonary infection. 7, active control of infection pulmonary infection is a common cause of the induction of critical signs, when the critical signs occur and aggravate the pulmonary infection. It is not possible to apply antibiotics that have a blocking effect on the nerve-muscle, such as polymyxins, aminoglycosides, lincomycin, clindamycin, vancomycin, quinolone antibiotics and sulfonamides. Penicillins, cephalosporins, macrolides, and chloramphenicol are available. For patients who have been tracheotomized, the most effective broad-spectrum antibiotics should be used according to the results of the bacterial culture drug sensitivity test of respiratory secretions, and the dose and course of treatment should be sufficient. For persistent pneumonia with high fever that does not subside, antibiotic intratracheal drip can be used, plus ultrasonic nebulization, which can increase the effect of controlling lung infection. 8, high-dose immunoglobulin intravenous drip therapy immunoglobulin treatment of myasthenia gravis crisis mechanism of action may be: (1) neutralization of pathological autoantibodies. (2) Compete with pathological autoantibodies to bind autoantigens, thus reducing autoantigen exposure and damage. (3) Inhibition of autoantibody production by plasma cells and reduction of cytokine production through negative feedback mechanisms. (4) Accelerate the degradation and metabolism of autoantibodies and immune complexes. At present, the main usage at home and abroad is: 400 mg/ for 5 days. 9.Plasma exchange therapy can rapidly remove pathological antibodies, circulating immune complexes, activated complement, cytokines, etc. and achieve the purpose of regulating autoimmunity. Plasma exchange is fast-acting and can effectively improve the symptoms of most patients with myasthenia gravis, and shorten the time of ventilator use and hospitalization of patients with myasthenia gravis, which is an effective treatment for myasthenia gravis. 10, psychological guidance, strengthen the confidence to overcome critical patients in a state of near death, with tension, anxiety, fear, fear of death of the contradictory psychology. We have to tell the patient that the medical staff is taking effective measures to help you get over the hump. Family members and medical staff are the spiritual pillars of the patient, encouraging the patient to overcome the disease with strong will in difficult times, telling the patient that the future is bright, the road is winding, and the final victory must belong to you.