Objective To explore the mortality and main causes of death of residents in Shannan City. Methods Death data in Shannan City in 2018 were collected. The data was encoded and classified according to the International Classification of Diseases (ICD-10). The 2010 standard population was used to standardize the mortality rate. Results In 2018, the mortality rate of residents in Shannan City was 359.53/100 000, and the standardized mortality rate was 421.446/100 000. The top 5 causes of death were cerebrovascular disease, heart disease, malignant tumor, respiratory disease and digestive system disease, accounting for 74.91% of the total deaths. Tuberculosis and hepatitis B were the main lethal infectious diseases, accounting for 90% of their total deaths. Conclusion Chronic non-communicable diseases were the main causes of death in Shannan City. Tuberculosis and hepatitis B among all infectious diseases are the focus of prevention. Targeted intervention measures should be taken to reduce the incidence of disease and death.