Abstract: Diffuse large B-cell lymphoma is a hematopoietic system disease with high incidence rate, rapid progression, and high mortality rate. Accurate prognosis evaluation through existing examination techniques is a major problem faced by scholars. At present, PET/CT has been widely used in the treatment monitoring and prognosis evaluation of lymphomas because of its unique advantage of simultaneously providing anatomical and functional images. However, a major controversy persists about which evaluation system provides accurate image assessment. This paper mainly introduces the application value of qualitative, semi-quantitative, and other new evaluation systems in the prognosis evaluation of diffuse large-B cell lymphoma.