在数据空间成为全球数据战略核心的背景下，如何构建高效、可信的政务数据共享机制是国家数字化转型的关键命题。文章聚焦数据空间理念在政务领域的关键实践欧盟“一次性原则”技术系统（OOTS），剖析其在数据空间背景下的运行机制。文章基于活动理论，构建“制度设计-技术架构-生态协同”三维框架，揭示了OOTS如何通过完备的法制与治理体系、标准化的互操作技术工具集以及多元主体协同网络，将数据空间所倡导的数据主权、互信互操作、可信连接与价值共创等核心原则落地。研究发现，OOTS的成功实践为解决传统政务数据共享的局限性、建立跨域信任提供了一套系统性的数据空间解决方案。因此，文章从完善顶层制度设计、构建互操作技术架构和培育协同治理生态三个维度，为我国在数据空间战略下优化政务数据共享机制提出了发展策略。

Against the backdrop of data spaces becoming the core of global data strategy, constructing an efficient and trustworthy government data sharing mechanism is a critical proposition for national digital transformation. This paper focuses on the European Union's "Once-Only Technical System" (OOTS), viewing it as a key practice of the data space concept in the government domain. The aim is to analyze its operational mechanism in the context of data spaces. Based on Activity Theory, this paper constructs a three-dimensional framework of "Institutional Design-Technical Architecture-Ecological Synergy". This framework reveals how OOTS implements the core principles advocated by data spaces-such as data sovereignty, mutual trust and interoperability, trusted connections, and value co-creation-through a complete legal system and givernance system, a standardized set of interoperable technical tools, and a collaborative network of diverse stakeholders. The study finds that the successful practice of OOTS provides a systematic data space solution for overcoming the limitations of traditional government data sharing and establishing cross-domain trust. Accordingly, this paper proposes strategies for optimizing the government data sharing mechanism under China's data space strategy from three dimensions: improving top-level institutional design, constructing an interoperable technical architecture, and cultivating a collaborative governance ecosystem.