随着我国城镇化水平的快速提升，推进城镇老旧小区改造成为提高居民幸福感和获得感、转变城市开发建设方式、推动城市高质量发展的重要任务。从已有的实践来看，政府主导下的城镇老旧小区改造在项目实施阶段还面临诸多挑战，需要结合实践优化完善城镇老旧小区改造的合作机制，建立稳定有效的多元主体合作关系，整合社会力量参与提升改造效率和质量，实现城市居住社区更新改造的常态化可持续发展。为此，本研究从政府、居民和社会资本参与城镇老旧小区改造的动力出发，探究城镇老旧小区改造责任的合理共担机制。首先，本研究通过理论分析，阐述了改造责任共担机制的参与主体、作用方式、主要功能及基础原则。其次，针对多元主体的合作困境，依次以收益分配、能力水平和社会角色为基础原则，设计责任共担的方案与思路，并对工作的组织开展提供指导依据。最后，综合分析并验证多元主体责任共担方案。研究发现，通过科学划分改造责任，能够建立并维护多元主体的合作关系，实现城镇老旧小区改造目标。为了积极引导居民个体有序参与集体行为，本研究以北京市的改造实践为例，指出居民住房价格在改造实施后显著提升3.1%，以项目收益为责任划分基础，居民有责任承担部分城镇老旧小区的改造工作，而考虑到居民个体收益存在差异，个体责任应当根据住房特征进行精准分配；为了提升改造效益，加强群体的内生动力，本研究经过模型推导和数值模拟，提出参与主体产出效率和成本控制水平对最优分担方案的指导作用，以能力水平为合作方案的设计基础，将城镇老旧小区的建设运营责任在政府、居民和社会资本之间进行分配；为了提升社会公共利益，本研究以城镇老旧小区内的养老问题为例，指出老年居民在城镇老旧小区中的潜在风险，从社会角色的定位要求出发，将改造责任和义务合理分配至三方主体。综合三个维度的共担依据，本研究基于责任共担机制提出了改造项目的合作方案，与专家评估结果相呼应，具有指导意义。本研究通过城镇老旧小区改造的合理共担机制研究，扩展了城镇老旧小区改造的研究框架，延伸了共担机制的内涵与应用领域，为多元主体合作的现实困境提供解决方案。合理共担机制的建立对于我国住房的全生命周期管理、社区的常态化更新、住房投资与消费新模式的培育具有重要意义。

With the rapid advancement of urbanization in China, promoting the renovation of old urban neighborhoods has become an important task for enhancing residents‘ sense of well-being and achievement, transforming urban development and construction methods, and promoting high-quality urban development. From the existing practice, government-led renovation of old urban neighborhoods faces many challenges during the implementation stage, and it is necessary to optimize and improve the cooperative mechanism for renovating old urban neighborhoods based on practical experience. This includes establishing stable and effective multi-party cooperation relationships, integrating social forces to enhance the efficiency and quality of the renovation, and achieving sustainable development of urban residential community renewal. This study focuses on exploring the sharing mechanism of renovation responsibilities for old urban neighborhoods, starting from the driving forces of government, residents, and social capital participation.Firstly, this study uses theoretical analysis to explain the participating entities, modes of action, main functions, and basic principles of the shared responsibility mechanism for renovation. Secondly, based on the principles of benefit distribution, ability level, and social roles, this study designs responsibility-sharing plans and ideas for multi-party cooperation challenges, and provides guidance for organizing and implementing such efforts. Finally, this study conducts a comprehensive analysis and validation of the multi-party responsibility-sharing plan.The study finds that scientific division of renovation responsibilities can establish and maintain multi-party cooperation relationships and achieve the goal of renovating old urban neighborhoods. To actively encourage individual residents to participate in collective behavior, this study uses the renovation practices in Beijing as an example and points out that after the implementation of renovation, the housing prices of residents have significantly increased by 3.1%. Based on the project benefits as the basis for responsibility division, residents are responsible for undertaking part of the renovation work of old urban neighborhoods. Since individual benefits may differ, individual responsibilities should be precisely allocated according to housing characteristics. To improve the renovation efficiency and strengthen the intrinsic motivation of the community, this study uses model deduction and numerical simulation to propose guidance on the optimal sharing plan based on the output efficiency and cost control level of participating entities. Using ability level as the basis for the cooperation plan design, the construction and operation responsibilities of old urban neighborhoods are allocated among the government, residents, and social capital. To improve social public interests, this study takes the elderly care issue in old urban neighborhoods as an example and points out the potential risks faced by elderly residents in the context of population aging. From the perspective of social role positioning, the renovation responsibilities and obligations are reasonably allocated to the three parties. Based on the shared basis of the three dimensions, this study proposes a cooperative plan for the renovation project based on the shared responsibility mechanism, which is consistent with the expert evaluation results and has practical significance.Through the research on the reasonable sharing mechanism of the renovation of old urban neighborhoods, this study expands the research framework of the renovation of old urban neighborhoods and extends the connotation and application fields of the shared mechanism, providing a solution for the practical challenges of multi-party cooperation. The establishment of a reasonable sharing mechanism is of great significance to the full lifecycle management of housing in China, the normalization of community renewal, and the cultivation of new models for housing investment and consumption.