Forests are the main body of terrestrial ecosystems; they are not only huge carbon stocks, but also have a positive effect on mitigating climate warming. Effective scientific forest carbon inventory measurement methods help to elucidate the global carbon cycle. Generally, however, due to the complex structure of forest ecosystems, the estimation of forest carbon measurements has had problems of low accuracy and high uncertainty. In recent years, a large number of methods for estimating forest carbon have been developed domestically and overseas. These methods mainly include forest vegetation and soil carbon estimation methods based on the inventory of sample plots, growth harvesting-based empirical model estimation and remote sensing estimation based on quantitative remote sensing and radar observations data, flux observations based on multi-scale forest ecosystem networks, and numerical simulation based on terrestrial ecosystem process models. In actual forest carbon measurement, different (or even multiple) carbon measurement methods are often used depending on the characteristics of different forest types and data acquisition. From the main methods of ecological process model simulation, remote sensing inversion, and data assimilation techniques, and based on multi-source data from carbon flux observation, a control experiment and remote sensing, multi-disciplinary, multi-process, and multi-scale integrated network observations have been developed to fully understand the spatial and temporal distribution characteristics of carbon sources and sinks in the cycle process. Systematic and integrated studies on carbon cycles have been carried out at regional, continental, and global scales, and their response to global changes and human activities, in order to establish an efficient and reliable carbon measurement system. These research aspects will be the development trend of forestry carbon measurements in the future. With the preparation of greenhouse gas emission inventories in various countries, China urgently needs a scientific method system to measure forest carbon sources and sinks in order to increase their international voice and dominance in ecological and environmental issues, and provide suggestions and support for sustainable forest management and ecological and environmental protection. This paper analyzes the main characteristics, advantages, and disadvantages of various forest carbon measurement methods, and discusses existing problems and the future development trend in forest carbon measurement methods, providing reference for forest carbon measurements under different spatial and temporal scales.