Abstract: Global warming has emerged as an increasingly prominent phenomenon, a trend that is closely linked to anthropogenic carbon dioxide emissions and the corresponding rise in atmospheric carbon dioxide concentrations. The effective mastery and application of observational methodologies for measuring carbon dioxide concentration and flux are essential prerequisites for addressing environmental challenges associated with carbon accumulation. This paper presents a comprehensive review of atmospheric carbon dioxide observation techniques and its associated data applications, covering ground-based, airborne, and spaceborne observation systems for carbon dioxide concentration monitoring, as well as the technical frameworks, underlying principles, and distinguishing characteristics of both "bottom-up" flux measurement approaches and "top-down" inversion techniques. The paper systematically examines the processes of observational data acquisition and their subsequent applications in scientific research, while also offering forward-looking insights into future research directions. Through this review, a deeper understanding of current carbon dioxide monitoring technologies is facilitated, providing valuable references for the advancement of global carbon observation systems. Furthermore, it contributes scientific support for China's climate change mitigation strategies and the formulation of policies aimed at achieving carbon peak and carbon neutrality goals.