作为超大城市治理现代化的创新实践，北京市接诉即办改革以 12345 市民服务热线为核心载体，构建起党建引领、多元协同、数据赋能的治理体系。本文基于马克思主义系统观，探析北京市接诉即办改革的运行机制、深层挑战与应对之策。研究发现，改革通过整合治理要素、凝聚多元主体、优化治理流程，实现了诉求解决率与群众满意率双提升，推动治理模式从被动响应向主动治理转型。面对跨部门协同壁垒、数据技术不完备、诉求分类精准度不足等问题，需进一步强化系统思维，完善协同机制、深化数字赋能、健全制度保障，为超大城市治理现代化提供 "北京经验"。

As an innovative practice in the modernization of governance in megacities, Beijing's 'Immediate Response to Complaints' reform uses the 12345 Citizen Service Hotline as its core platform, building a governance system led by Party construction, coordinated by multiple parties, and empowered by data. Based on the Marxist system perspective, this paper explores the operating mechanism, deep-seated challenges, and countermeasures of Beijing's 'Immediate Response to Complaints' reform. The study finds that the reform, by integrating governance elements, consolidating multiple actors, and optimizing governance processes, has achieved simultaneous improvements in complaint resolution rates and public satisfaction, promoting a shift in governance mode from passive response to proactive governance. In the face of cross-departmental coordination barriers, incomplete data technology, and insufficient accuracy in complaint categorization, it is necessary to further strengthen system thinking, improve coordination mechanisms, deepen digital empowerment, and enhance institutional guarantees, providing a 'Beijing experience' for the modernization of governance in megacities.