Care for senior citizens in their late life has become an increasingly striking issue in our ageing society. Mutual-support old-age care is becoming an important dimension in solving the problem. Additionally, this mode embodies vital social practice value in changing the passive elderly care idea and achieving the positive aging population. From the perspective of the sociology of law, the author investigated the forms of organizations , types of activities, and bonds of beliefs in the practice of mutual-help-based elderly care in Caiyuan Town, and holds that the sustainable development of mutual-help-based elderly care requires the government to fill the gaps in laws, regulations, and policies, and calls for social organizations to proactively participate in elderly care services, to provide indispensable support in law and assistance in society for the elderly to take part in social activities, establish harmonious interpersonal relationships, and achieve their life values.