Through the study of binary labor market and two forms of employment, the effect object of prolonging the retirement age is determined. Then the paper explore the transmission mechanism extending retirement age affect human capital. Through the media of the relevant factors which influence human capital stock, extending retirement age affects the quantity and the quality of human capital respectively. And the influence of extending retirement age on the human capital is revealed from the individual, structure, efficiency of resource allocation, economic and social justice and some related institutions. The implementation of extending retirement age is systemic projects where a slight move in one part may affect the whole situation, subsequently, we should take all factors into consideration, realize comprehensive, coordinate and sustainable development of population, economic and society.