As the basis of global carbon cycle research, terrestrial ecosystem carbon storage is closely related to land use change. Ecological protection red lines, permanently basic farmland protection red lines, urban development boundary lines (referred to as the "three lines") are the core of the national space planning, which can better restrict land use, and then affect carbon storage. Taking Wuhan City circle as an example, this paper uses the Markov-FLUS composite model to simulate land use pattern of this region under the "three lines" constraints, and uses the InVEST model to study the impact of land use change on carbon storage under different scenarios quantitatively. The results showed that:① The area of the cultivated land, forest land, grass land and unused land decreased by 1267.582 km², 112.703 km², 24.896 km² and 42.14 km² in Wuhan City circle from 2000 to 2015, while the construction land and water area increased by 1092.282 km² and 355.039 km². In 2035, under the "three lines" constraint scenario, the reduced area of the cultivated land is less than the natural development scenario, and the area of forest land is increased, and the new construction land is guided to gather within urban development boundary lines. ② The total carbon storage showed a continuous decline trend in Wuhan City circle from 2000 to 2015, and the carbon storage of Wuhan City decreased the most. Under the "three lines" constraint scenario, the decline of carbon storage and average ground carbon density is observably smaller than the natural development scenario, and the reduction of carbon storage in Wuhan City is only 44.89% of the natural development scenario. ③ The conversion between cultivated land and construction land is the main reason for the drastic changes of carbon storage. There is a significantly negative correlation between land use intensity and carbon storage, and the lower intensity zone has the highest carbon storage. Therefore, under the "three lines" constraints, the land use of Wuhan City circle can reasonably coordinate the layout of ecological-agricultural-urban functional space, and slow down the loss of carbon storage, which is of great significance to the optimization of regional national space.