Mitral stenosis is mainly caused by recurrent episodes of rheumatic fever, so prevention of recurrent episodes of rheumatic fever is the key to preventing the occurrence and development of mitral stenosis. Once a patient is clearly diagnosed with mitral stenosis, treatment should be actively taken. Clinical treatments for mitral stenosis include mitral valve closed dilatation and mitral valve balloon dilatation. Currently, the main treatment methods for mitral stenosis are: mitral closed dilatation, which is indicated for patients with mild septal stenosis without subvalvular structural changes, without atrial fibrillation and intra-atrial thrombus, and without combined mitral or tricuspid valve insufficiency. Mitral valve balloon dilatation, a relatively new radiological interventional technique. Mitral valvuloplasty, for patients with severe stenosis with mild subvalvular adhesions and valve thickening, is also indicated in patients with combined tricuspid valve insufficiency and intra-atrial thrombus and atrial fibrillation. Mitral valve replacement is indicated in patients with severe lesions of the valve and subvalvular structures and with calcification of the valve, subvalvular adhesions, funnel-shaped orifices, or in patients with valve stenosis after closed dilatation, and in patients with combined infective endocarditis. For mitral stenosis caused by rheumatic fever, the prevention and treatment methods are as follows: 1, prevention and control of pharyngeal streptococcal infection and recurrence of rheumatic activity 2, prevention of infective endocarditis, exercise for cold tolerance, and timely treatment of streptococcal infection. Also pay attention to oral hygiene, adhere to regular drama teeth, dental cleaning, etc. 3.Appropriate rest, limit sodium intake, and take oral diuretics to improve the status. 4.Pay attention to the changes of heart rate and heart rhythm. 5, usually pay more attention to oral hygiene, timely treatment of hidden lesions. 6.Pay attention to keep warm and try to avoid upper respiratory tract infection. 7.For patients who have been bedridden for a long time and cough with phlegm, nursing staff should help patients pat their backs to help them cough up the phlegm and actively take medication to avoid the occurrence of pneumonia. Keep the residence clean and fresh, and ventilate frequently. 8. Regular outpatient follow-up review.