“Forest is a carbon sink” vividly explains the strategic position of forests in China’s national ecological security as well as sustainable development of human economy and society. As the primary contributor of carbon sequestration in terrestrial ecosystems, forest carbon fixation is an important path to realize China’s “carbon peaking and carbon neutrality” vision. With years of ecological civilization construction in China, both the storage and the function of forest carbon sink were steady improved, contributing to global forest carbon sink remarkably. However, in relation to the vast territory, complex habitat types, and the momentum of old-school forest management and silviculture, pressing needs emerge for alternative solutions as to sinking forest carbon in a way more effective for the purpose of achieving “carbon peaking” by 2030 and “carbon neutrality” by 2060, particularly in the exacerbation of climate change. Oriented to the five forest carbon pools and their biotic and abiotic driving factors, this paper systematically explores modern carbon sink assessment methods such as forest field surveys and model simulations, and then focuses on prospective means to improve forest carbon sinks. We envisage that trending researches should firstly focus on building a multi-scale, all-round ecosystem monitoring network and system; secondly, establish a comprehensive analysis framework that incorporates monitoring and assessment for reducing the uncertainty of carbon inventory; last but not the least, establish a sustainable financial market for forestry carbon, and facilitate with policy support, forming multi-disciplinary talent teams with strengthened international cooperation to improve the quality and efficiency for the financial system of forestry carbon.