By building a theoretical model of endogenous automation level, the impact of aging and automation on economic growth is studied. The equilibrium results show that automation plays an mediating effect in the role of aging on economic growth, and the pressure of aging will promote the improvement of automation, and further promote the growth of output, so as to offset the negative impact of the reduction of labor on output. After empirical analysis using provincial panel data in China, the results also verifies that this mediating effect is a partial mediating effect. The impact of aging on economic growth through automation is about 18% of the total impact of aging on economic growth. However, with the improvement of automation level, the mediating effect shows a trend of weakening. Therefore, on the basis of the traditional “machine replacement” automation, more advanced artificial intelligence must be realized in order to provide a good foundation for sustained economic growth.