Objective To understand the prevalence of smoking and drinking among residents ≥ 30 years old in Chengdu, and to investigate the death attributable to smoking and drinking and its effect on life expectancy. Methods The data sources were data of the causes of death of residents in the 2018 Sichuan Health Statistical Yearbook, the health survey data of Chengdu residents in the natural population cohort in southwest China, and the data of smoking and drinking related diseases and their relative risk in the global disease burden of the World Health Organization. The counterfactual attribution method was used to calculate the number of attributable deaths and life expectancy loss caused by smoking and drinking. Results The life expectancy of 30-year-old residents in Chengdu was 53.91 years (51.52 years for males and 56.48 years for females). The total number of deaths attributed to smoking was 14 370, with chronic obstructive pulmonary disease (4 926), lung cancer (4 234), and esophageal cancer (1 578) ranking the top three. The total number of deaths attributed to drinking was 2 185, among which cerebrovascular disease, esophageal cancer, and liver cirrhosis were the three leading causes of death attributable to drinking. The loss of life expectancy caused by smoking was 2.03 years (3.47 years for males and 0.39 years for females), and the loss caused by drinking was 0.28 years (0.48 years for males and 0.04 years for females). Conclusion Smoking and drinking cause a great loss of life expectancy of Chengdu residents and impose a huge disease burden on the death from respiratory system, digestive system, cardiovascular and cerebrovascular diseases.