Forests have a significant impact on the global carbon cycle. Forest-carbon-sinks are a key component of terrestrial carbon sinks, as evidenced by a growing literature in the international community. This study identified 4,973 relevant peer reviewed studies from 1990-2021 using Web of Science and the bibliometric tool “CiteSpace”. These studies formed the foundation of a knowledge map of literature co-citation and keyword co-occurrence networks, which were used to and analyze trends of forest carbon sink research. This study found that: (1) the number of articles on forest carbon sink research continues to grow, suggesting that forest carbon sinks remain a high-priority research topic both in China and abroad; (2) the main topics of research include methodological developments in the measurement of forest carbon balance, generalizing the underlying theory of the estimation of stable forest carbon sink areas, application of theory to practice, and understanding the scale of global carbon sinks’ influence; and (3) the main focus of domestic research includes methods for estimating carbon stocks and balance of China's forests, and the theoretical integration of China's stable forest carbon sinks. Therefore, research priorities have shifted from the measurement of China's forest carbon stock to the identification of carbon sinks, before finally focusing on the generating mechanisms of China's forest carbon sinks. Currently, domestic research trends are gradually converging with international priorities and China's academic contributions have gained international recognition. In the future, China needs to increase support for systematic investigations and monitoring of forest ecology and build an integrated "sky-air-ground" carbon sink calculation system for more accurate monitoring of the scale of carbon sinks. Moreover, it is necessary to provide an accurate and comprehensive assessment of the contribution of forest carbon sinks to China’s goals, so as to achieve carbon neutrality.