Diffuse large B-cell lymphoma is the most common subtype of lymphoma in our country and is aggressive. Most of them express CD20 on the surface, so if treated with rituximab, a monoclonal antibody containing anti-CD20, about 50% can be cured. However, diffuse large B-cell lymphoma is another particularly suppressive disease, specifically expressing certain genes, such as the commonly referred to diffuse large B double-hit lymphoma, which is defined as expressing MYC and BCL-2 positive or MYC and BCL-6 positive, with a very poor patient prognosis. In addition, diffuse large B-cell lymphoma is classified into low-risk, low-medium-risk, high-medium-risk, and high-risk according to the International Prognostic Index, and the prognosis is significantly different, for example, the 5-year survival rate is above 70% for low-risk and around 30% for high-risk lymphoma. If it has invaded the bone marrow, or specific sites, like central lymphoma, adrenal lymphoma, or testicular lymphoma, the prognosis is relatively poor. Therefore, for diffuse large B-cell lymphoma, a comprehensive analysis should be used, and according to the stage, staging, special sites, and gene expression, appropriate radiotherapy and even hematopoietic stem cell transplantation should be used, which can improve the survival rate of patients.