人口老龄化是我国目前应对的重要社会问题之一，截止至2021年末，我国人口总数已达到141260万人，其中65岁以上的老人为20056万人，占比14.2%。随中国经济的发展，城镇化率迅速提高，截止至2021年末，我国的城镇化率已达64.72%，同时在我国最新的“十四五”规划中，也明确要在2025年以前城镇化率将达到65%以上。城镇规模的快速增长，加快了城市更新的步伐，为改善原有老旧小区基础设施不完备、解决老年人上下楼出行问题，我国进行了城镇老旧小区综合改造和治理，而这其中的电梯加装工程备受社区居民的关注。电梯加装具有其专业性和综合性的特点，一举一动又关系着普通百姓切身利益，因此在实际推进过程中稍有不慎便会引发社会矛盾。在我国大力推进城市现代化治理体系建设的今天，引入多元治理为社区治理的新实践，在电梯加装项目管理中各方主体通过协商平台共同参与其中，但在实际实施中，由于各方主体的权责等不平衡、以及对电梯加装项目缺乏专业知识支持、协商机制尚未完善等原因导致效果并不理想。基于以上背景，本文并以北京市丰台区云岗地区为例，回溯该地区自2008年起至今的电梯加装典型案例，通过田野调查法收集项目信息，深入社区进行问卷调查法和访谈，并结合相关的文献研究，探讨项目全生命周期过程中的多元治理问题；运用公共管理学中的多元治理理论与工程项目管理学中的项目全生命周期理论，阐述在电梯加装过程中相关参与主体的权责与作用。从其成功的经验与失败的教训中总结各参与主体，尤其是专家及专家团队在整个项目进程中的表现，着重分析专家在项目全生命周期管理中的重要作用与价值，研究的意义在于完善在解决高专业化和强实践性的社会公共问题时的多元治理的理论视角范围，并对此类公共管理实践贡献对策与建议。通过实证分析案例各阶段过程中出现的问题及成因分析，给出相应结论。第一，原有电梯加装项目的管理为自上而下的线性模式，缺乏反馈机制，多元参与的动力匮乏，导致项目整体管理效果不理想，单位制的一元独大模式亟待转变。第二，在工程项目全生命周期的决策、实施、运营和后评价四个阶段中，专家团队的作用没有充分发挥。第三，在电梯加装项目中的多元主体间互动不足，需要进一步加强并创新灵活的机制。最后对应问题给出具体对策，从项目全生命周期角度提出建立闭环管理机制，提升专家团队的作用，增强多元治理配合机制，调动多元主体的积极性等方面给与相应的政策建议。

Population aging is one of the most important social issues in China. By the end of 2021, the total population of China will reach 141.26 million, of which 20.56 million will be over 65 years old, accounting for 14.2%. With the development of China's economy, the urbanization rate is rapidly increasing, and by the end of 2021, China's urbanization rate has reached 64.72%, while in China's latest 14th Five-Year Plan, it is also clear that the urbanization rate will reach over 65% by 2025. The rapid growth of urban scale has accelerated the pace of urban renewal, and to improve the original old neighborhood infrastructure is incomplete and to solve the problem of elderly people going up and down the stairs, China has carried out comprehensive renovation and management of old urban neighborhoods, and the elevator retrofitting project is of great concern to community residents.Elevator retrofitting has its professional and comprehensive characteristics, and every move is related to the vital interests of ordinary people, so the actual process of promoting the slightest inadvertence will lead to social conflicts. In China today, we are vigorously promoting the construction of a modernized urban governance system and introducing multi-dimensional governance as a new practice of community governance. In the project management of elevator retrofitting, all parties participate in the project through a consultation platform, but in actual implementation, the results are not satisfactory due to the imbalance of the rights and responsibilities of all parties, the lack of professional knowledge support for the elevator retrofitting project, and the imperfect consultation mechanism.Based on the above background, this paper takes the Yungang area in Fengtai District of Beijing as an example, retraces the typical cases of elevator retrofitting in the area from 2008 to the present, collects project information through field survey method, conducts questionnaires and interviews in the community, and combines relevant literature research to explore the issue of multi-governance in the whole life cycle of the project; uses the theory of multi-governance in public management and the theory of the whole life cycle of the project in engineering project management. Using the theory of pluralistic governance in public management and the theory of project life cycle in engineering project management, we explain the rights, responsibilities, and roles of relevant participating subjects in the process of elevator retrofitting. The significance of the study is to improve the scope of theoretical perspectives on multi-governance in solving highly specialized and practical social and public problems and to contribute countermeasures and suggestions to such public management practices.Through empirical analysis of the problems and causes that emerged during each stage of the case, corresponding conclusions are given.First, the management of the original elevator retrofitting project is a top-down linear model, lacking a feedback mechanism and a lack of motivation for pluralistic participation, resulting in unsatisfactory overall project management and a unitary, monolithic model that needs to be transformed.Secondly, the role of expert teams is not fully played in the four stages of decision-making, implementation, operation, and post-evaluation in the whole life cycle of engineering projects.Third, the interaction between multiple subjects in the elevator retrofitting project is insufficient and needs to be further strengthened and innovated with flexible mechanisms.Finally, specific countermeasures are given in response to the problems, and corresponding policy suggestions are given from the perspective of the whole life cycle of the project, such as establishing a closed-loop management mechanism, enhancing the role of the expert team, strengthening the mechanism of multiple governance cooperation, and mobilizing the enthusiasm of multiple subjects.