As China’s aging population continues to deepen， relying solely on the government has been unable to meet the needs of pension services in China， the powerful assisting role of Civil Society Organizations（CSOs） can not be ignored， the concept of social capital increases more and more in the field of public health. From the perspective of middle social capital theory， this study explored external social capital factors， analyzed the difficulties faced by CSOs in the field of the pension services， and explored the strategies to cultivate external social capital， to improve the quality and level of the pension services by CSOs， and to promote the development of national pension services industry.