Population aging has become an important factor restricting China’s economic growth. Firstly, in order to investigate the economic effect human capital in aging society, the endogenous growth theory model including aging factors is established to study the optimal scale of capital investment. Secondly, based on China’s panel data from 2010 to 2018, this paper uses the GMM etc estimation methods to test the contribution of human capital to economic growth. The empirical conclusion is that with the restriction of aging, the economic output elasticity of human capital in China is lower than the economic output elasticity of physical capital, namely population aging have an negative impact on the economic effect of human capital and the investment return period. Under the background of increasingly serious aging, in order to promote the effect of human capital,local governments should adjust the two types of capital investment structure according to their own economic factor endowment and development foundation, so as to mitigate the economic impact caused by aging.