Systemic lupus erythematosus (SLE) is a disease that can be divided into several types. SLE is an autoimmune disease that involves multiple body systems and organs, with complex clinical manifestations and a recurrent course. SLE can be divided into two categories: systemic lupus erythematosus (SLE) and discoid lupus erythematosus (DLE). Subacute cutaneous lupus erythematosus (SCLE) is a skin lesion that is intermediate between discoid lupus erythematosus and systemic lupus erythematosus. The epidemiology of SLE is reported in a multi-regional survey in the U.S., with a prevalence of 14.6-122/100,000, and in a large series of one-time surveys conducted in Shanghai among female textile workers, with a prevalence of 70/100,000, and up to 115/100,000 among women. The clinical manifestations are complex and varied. Most patients have an insidious onset and start to involve only one to two systems, showing mild arthritis, rash, occult nephritis, thrombocytopenic purpura, etc. Some patients are stable in a subclinical state or light lupus for a long time, some patients can suddenly change from light to severe lupus, and more patients gradually develop multi-system damage from light; some patients involve multiple systems at the onset and even show lupus crisis. The natural course of SLE is mostly characterized by alternating exacerbations and remissions.