This paper discussed the impact of economic development on carbon emissions in Sichuan Province from 1990 to 2020 and put forward some suggestions to accelerate the development of a low-carbon economy. Firstly, the land use type was reclassified, then the IPCC coefficient method was used to calculate the land use carbon emissions, and then the driving factors affecting the carbon emissions were obtained by the log-average factor index (LMDI) method. Finally, the decoupling elasticity index and its influencing factors were obtained using Tapio decoupling model. The results showed that: (1) Carbon emissions in Sichuan Province increased significantly, with a growth rate of 218.7% from 1990 to 2020. Per capita GDP, land use structure and land use intensity per unit GDP were the main reasons for carbon emissions change. (2) Sichuan Province achieved strong decoupling during 1995-2000 and 2015-2020. However, it was in a state of expanding connection during 2000-2005, and the economic pressure on the environment reached the maximum. (3) Per capita GDP was the main factor promoting the elastic growth of decoupling index, while land use intensity per unit GDP is the main reason inhibiting the elastic growth of decoupling index.