China's aging population continues to deepen, relying solely on the government has been unable to meet the needs of elderly care services in China, the powerful role of civil society organizations can not be ignored, the concept of social capital more and more in the field of public health.From the perspective of meso social capital theory, this paper discusses external social capital elements, analyzes the difficulties faced by civil society organizations in the field of old-age care, and discusses the strategies to cultivate external social capital, improve the quality and level of old-age care services provided by civil society organizations, and promote the development of national old-age care service industry.