Computing‒electricity synergy is a critical pathway to address the explosive growth in artificial intelligence computing demand and the challenges in global energy transition. The quality of its development is vital for advancing the carbon peaking and carbon neutralization goals as well as the sustainable upgrading of the computing infrastructure. This study reviews the current state of computing‒electricity synergy, identifies challenges in terms of physical foundations, enabling technologies, market mechanisms, and industrial ecosystems, and constructs a comprehensive computing‒electricity synergy framework spanning the planning‒construction‒operation‒market chain. Moreover, it establishes a hierarchical functional architecture encompassing physical resources, data fusion, coordinated optimization, application services, and support systems. The study also analyzes key technologies in computing‒electricity synergy across sensing, communication, computing, control, and security dimensions, as well as an indicator system covering energy efficiency, carbon efficiency, coordinated response, and economic value, to provide a unified benchmark for evaluating synergy capabilities and quantifying outcomes. Typical application scenarios are explored, including unit-level, link-level, regional-level, and global-level synergies, clarifying the values of computing‒electricity synergy in energy efficiency enhancement, carbon efficiency optimization, cross-domain coordination, and system resilience. Further prospects are outlined for trends in architecture coupling, technological enablers, mechanism innovation, and ecosystem cultivation, proposing that computing‒electricity synergy will gradually advance along a spiral path from information interoperability to business coordination and ultimately ecosystem integration. The study demonstrates practicality, systematicity, and foresight, revealing the strategic value and development direction of computing‒electricity synergy.