Making full use of public libraries to enrich the grass-roots elderly care service system can not only reduce the comprehensive cost, but also achieve good results. Not long ago, general secretary Xi Jinping made important instructions on the work of ageing, emphasizing "increasing institutional innovation, policy supply and financial input, improving and perfecting the work system for the elderly, strengthening the allocation of grass-roots forces, and accelerating the improvement of social security system, pension service system and health support system". As an important window for the state to provide free public cultural services to the society, public libraries should play a greater role and become an important part of improving the elderly care service system. The elderly group is one of the important service objects of public libraries. Providing them with thoughtful reading service is a responsibility and obligation of public libraries. China's public library law clearly stipulates that public libraries established by the government should take into account the characteristics of the elderly, the disabled and other groups, actively create conditions and provide literature information, barrier free facilities, equipment and services suitable for their needs. Public libraries have many advantages in serving the elderly. For example, public libraries do not have too many restrictions on the age and physical conditions of service objects, and free services also exempt many elderly readers from economic concerns. Because of its special attribute of public cultural services, public libraries must always maintain a safe, hygienic, clean and orderly library environment, which is particularly important for the elderly. Nowadays, public libraries pay more and more attention to the establishment of emergency mechanism. When elderly readers are ill in the library, they can respond and help them timely and efficiently, so as to ensure the physical and mental health and safety of the elderly to the greatest extent. Nanjing Library has arranged special funds to purchase accident insurance for all elderly readers entering the library, so that the majority of elderly readers can read safely and stay safely in the library, which has been highly praised for many years. Similar service innovations are emerging in public libraries everywhere. Making full use of public libraries to enrich the grass-roots elderly care service system can not only reduce the comprehensive cost, but also achieve good results. Nowadays, more and more elderly people pursue "learning" and "happiness" on the basis of "providing for the elderly". Public libraries can play an irreplaceable role in promoting high-quality elderly care services. Reading has the brain function of delaying aging, and the massive and diversified cultural resources of public libraries can provide effective services for the reading and browsing needs of all kinds of elderly groups. For the elderly readers who like research, the public library provides a rare literature pool. Nowadays, in order to improve the quality of public cultural services, local public libraries have come up with ideas one after another. Nanjing Library launched the "Tao style" reader recommendation and purchase business earlier. Readers can directly take the books they need home from the cooperative bookstore for reading and use, and finally return the books directly to the library, so as to realize the service purpose of not being owned by readers, but for readers. For the majority of readers, including elderly readers, this is undoubtedly a pragmatic and efficient warm-hearted move. The 14th five year plan and the long-term goal outline for 2035 propose to promote the free opening and digital development of public cultural venues such as public libraries, cultural centers, art galleries and museums. In order to let the elderly share the dividends of the times, public libraries have launched targeted aging services. For example, while fully implementing online reservation services, many public libraries have reserved telephone reservation channels and offline reservation windows for the elderly; Some public libraries allow the accounts of the elderly to be bound with their children's accounts, and children can help the elderly with various online operations. The Nanjing library has also organized a multi-stage network for public service training for the elderly readers. The elderly readers or their children click on the remote borrowing of WeChat official account, so that books can be sent to the home free of charge to meet the needs of home reading. Facing the future, how to give better play to the public cultural service function of public libraries and help build a high-quality elderly care service system still needs our in-depth research and continuous exploration. With the continuous improvement of various elderly care service functions, public libraries will be able to gather a wider range of grass-roots resources and forces to promote the elderly to better share the fruits of reform and development and enjoy a happy old age. (outlook new era)