Abstract: The research progress of carbon monitoring and accounting methods is reviewed, and the three major carbon monitoring technology systems (direct measurement method, model simulation method and remote sensing monitoring method) as well as the principles, applications and development trends of three carbon accounting methods (emission factor method, mass balance method and process analysis method) are systematically expounded. It is shown that carbon monitoring and accounting technology is evolving in the direction of high precision, wide coverage and strong practicability, providing important support for coping with climate change and achieving carbon neutrality goals. In terms of carbon monitoring methods, the direct measurement method realizes real-time monitoring of the emission source by means of sensor technology （ such as TDLAS and FTIR ）. Its data compliance is strong and the traceability ability is outstanding, but there are limitations such as high equipment cost and insufficient representativeness of distribution points. It can be effectively alleviated by domestic substitution and mobile monitoring supplement strategies. The model simulation method uses atmospheric transmission models such as WRF-Chem to fill the monitoring gap in remote areas, and improves the accuracy through high-resolution simulation and data assimilation technology, but it faces the challenges of input parameter uncertainty and high demand for computing resources. The remote sensing monitoring method relies on satellites （ OCO−2 ） and unmanned aerial vehicles （GHGSat） to build a ' satellite-air-ground ' integrated network to achieve multi-scale coverage from global carbon flux assessment to accurate monitoring of industrial point sources, but it needs to break through the technical bottlenecks of cloud interference and inversion algorithm dependence.In the carbon accounting method system, the emission factor method is widely used in power, steel and other industries due to its simplicity of operation, but the problem of factor deviation needs to be solved urgently through the construction of localized database. The mass balance method shows high-precision advantages in process industries （ such as cement and chemical industry ） based on carbon flow tracking, and it is necessary to strengthen the deployment of online monitoring equipment to improve data quality. The process analysis method realizes the refined emission management of complex industries through the mechanism model （ Aspen Plus ）, but it is limited by the level of enterprise informatization and the cost of model development. In terms of policy driving, China 's " dual carbon " system promotes the standardization process of monitoring and accounting, and the 12 core standards issued in 2024 strengthen the mechanism of measurement certification and data mutual recognition of monitoring equipment. The implementation faces challenges such as cross-sectoral data islands and lack of accounting for emerging emission sources （ such as data centers and hydrogen energy industries ）. It is necessary to break through through the construction of national carbon monitoring platforms and the development of special methodologies. It is pointed out that in the future, multi-technology integration （ such as AI-driven 4D−Var data assimilation ） should be strengthened, the“monitoring-reporting-verification”system should be improved, and international cooperation such as the Global Carbon Monitoring Program （ GCP ） should be deeply involved to comprehensively enhance the support for carb