The tropical Pacific Ocean is the most active region for sea-air interactions globally, where carbon exchange plays a critical role in the global carbon cycle and climate change. Analysis of observational and simulation data reveals the spatiotemporal variation characteristics and key controlling processes of sea-air CO₂ flux (FCO₂) in this region, along with projections of its future trends. The tropical Pacific serves as a carbon source for atmospheric CO₂, releasing an average of approximately 0.27 Pg C/a. Spatially, the flux shows an asymmetric east-west “source-sink” pattern and a quasi-symmetric north-south “sink-source-sink” pattern. Temporally, it varies with the ENSO cycle, with seasonal minima in February-March and maxima in September-October. The processes governing air-sea carbon exchange are both controlled and complex. Atmospheric CO₂ concentration is the dominant external forcing controlling the long-term variability of air-sea FCO₂, while modulating its interannual-decadal variability through ENSO. Wind speed is the primary dynamic factor governing the gas transport rate between these two environments. Additionally, ocean current mixing directly drives carbon exchange through horizontal transport. Sea surface temperature and freshwater input indirectly influence the partial pressure of carbon dioxide in seawater by altering the gas’s solubility and diluting inorganic carbon and total alkalinity, respectively. Furthermore, these factors are crucial for maintaining ocean stratification and affecting the vertical exchange of water masses. Many of these elements are also intricately linked to marine biogeochemical processes, thereby regulating sea-air carbon exchange through the seawater carbonate balance system. Under increasing anthropogenic CO₂ emissions, rising atmospheric CO₂ will continue to dominate the long-term evolution of tropical Pacific air-sea CO₂ exchange, potentially reshaping regional carbon source-sink patterns through processes associated with global warming, including reduced seawater buffering capacity, changes in thermocline structure, and altered ENSO variability. Consequently, it is imperative to enhance research on the processes governing sea-atmosphere carbon exchange in this region in response to global warming, and to elucidate the conditions and reversibility associated with source-sink transformations.