Objective To analyze the death dtstus, the change trend of average life expectancy and the key age groups affecting average life expectancy in registered population in Shaoxing, Zhejiang province.

Methods Jiang's brief life table, Joinpoint regression model and Arriaga decomposition method were used to analyze the total cause-of-death surveillance data in Shaoxing from 2015 to 2022. The annual percentage change (APC) and average annual percentage change (AAPC) of premature death rate from major chronic diseases and life expectancy and the contribution rate of different age groups to the increase of life expectancy were calculated.

Results The average life expectancy in Shaoxing increased by 1.52 years from 2015 to 2022 (AAPC=0.28%). The average life expectancy was 79.37–81.55 years from 2015 to 2020, with an upward trend (APC=0.53%). The average life expectancy was 81.55–80.89 years from 2020 to 2022, with a downward trend (APC=−0.34%), but the difference was not significant (P>0.05). The premature death rate of major chronic diseases decreased from 12.46% in 2015 to 9.99% in 2022, a decrease of 2.47% (AAPC=−3.61%). The total contribution rate of the top five age groups for increased life expectancy was 59.41%. The top five age groups were age group 1–4 years (14.32%), age group 0–1 year (12.21%), age group 70–74 years (12.16%), age group 65–69 years (10.80%) and age group 75–79 years (9.91%). The age group 15–24 year of men had negative contribution to life expectancy with contribution rate of −1.62%.

Conclusion From 2015 to 2022, the average life expectancy in Shaoxing generally showed an increase, which was mainly due to the decline in the mortality rate in infants and the elderly. However, the age group ≥85 years and age group 15–24-years of men had negative contribution to the increase in life expectancy. Comprehensive prevention and control measures targeting key populations and key diseases should be taken to further increase the average life expectancy of Shaoxing residents.