Hepatitis D virus （HDV）， as a defective virus， relies on the envelope protein of hepatitis B virus （HBV） to complete replication and transmission. Chronic hepatitis B （CHB） patients comorbid with HDV infection may experience significant acceleration of liver disease progression and a significantly higher risk of serious complications such as liver cirrhosis and hepatocellular carcinoma （HCC） compared with the patients with CHB alone， which poses a serious threat to the life and health of patients. At present， the coverage rate of HDV screening needs to be improved， and some patients with HBV/HDV co-infection have not been found in time. Therefore， strengthening the understanding of HDV among clinicians， expanding the scope of HDV screening， identifying patients with infection in a timely manner， and performing standardized antiviral therapy and long-term follow-up management are of great significance for improving the prognosis of patients， reducing disease burden， improving the quality of life of patients， and achieving the global goal of “eliminating viral hepatitis as a public health threat by 2030”.