Steroid myopathy, also known as corticosteroid polymyopathy, is muscle weakness and myasthenia due to increased endogenous corticosteroids or steroid treatment. The pathogenic mechanism is not well understood. Rheumatology has a high incidence of steroid myopathy due to the use of hormones in many patients in the treatment phase of the disease, especially with the use of high doses of hormones. The diagnosis of steroid myopathy is mainly based on the following points: 1, the application of steroid hormones for the treatment of polymyositis or other connective tissue diseases when muscle weakness or muscle weakness is aggravated, 24-hour uric acid excretion increases, while the serum CK level is relatively stable; 2, the application of steroid hormones in the process of muscle weakness with severe manifestations of Cushing syndrome, such as hypertension, electrolyte disorders, water and sodium retention muscle biopsy showed selective type 2 muscle fiber atrophy and increased fat droplets in type 1 muscle fibers; 4. muscle weakness resolved after discontinuation of steroids.