Abstract: This article introduces population structure factors into a two-sector neoclassical non-balanced growth model, and theoretically demonstrates the impact of ageing population structure on the transformation of industrial structure to service-oriented and economic “structural deceleration” through the mechanism of demand transfer. Secondly, empirical research based on panel data from 287 prefecture level and above cities in China from 2003 to 2020 shows that for every 1% increase in the proportion of urban residents aged 65 and above, the degree of industrial structure servitization will increase by 0.025 units, leading to a decrease of 0.445 percentage points in the growth rate of per capita real GDP. After decomposing the effects of different demographic factors, we find that the aging of the urban registered residence population also leads to economic slowdown by promoting the service-oriented transformation of industrial structure; population inflow can slow down the process of service-oriented transformation of urban industrial structure, thereby promoting its economic growth, and has a certain diluting effect on the impact of the service-oriented transformation of industrial structure and economic slowdown caused by the aging of the registered residence population. Further analysis also shows that the sustained improvement of productivity growth in the service industry and the transformation and upgrading of the internal life service industry to productive service industry can help weaken the “structural slowdown” impact of the service-oriented transformation of the industrial structure; and accelerate the accumulation of human capital to achieve the transformation from “population dividend” to “talent dividend”, which can also alleviate the negative impact of population aging on economic growth. The conclusion of this article can provide certain experience and reference for China to adapt to the current trend of population s

Key words: demographic changes, industrial transformation, structural deceleration, population aging, population mobility