Land use and land cover change is an important factor affecting global environmental change, and has become a hot spot issue in global change and ustainable
development research. The main causes of carbon stock changes in ecosystems are regional land use changes and land use intensity. In this paper, we use the CLUMondo model to simulate the distribution of the land system in 2020 and calculate the carbon stock of the ecosystem in this case based on its output results using the carbon module of InVEST model. The results show that the CLUMondo model has the ability to simulate complex land systems, and the calculated overall carbon density of the inner watershed of the Tibetan Plateau
is 123.10 Mg/ha on average, and the RMSE is 49.67 when compared with the full carbon data of soil samples from WoSIS and the multispectral remote sensing inversion carbon stocks, which is relatively similar. Therefore, the method of calculating carbon stocks after simulating the land system using the CLUMondo model is feasible. The carbon stock results can be used to assess land use scenario changes and can provide a scientific basis for sustainable development and ecosystem carbon neutrality.