Abstract: As a critical region for ecological protection and carbon sink management, Neijiang City faces increasing challenges from changes in land use structure impacting ecosystem carbon storage. Utilizing land use data from 1994, 2004, 2014, and 2024, this study employs the InVEST model’s carbon storage module to systematically analyze the spatiotemporal evolution of land use patterns and their effects on carbon storage within the region. The results indicate that (1) land use changes primarily occurred among cropland, forestland, and built-up areas; cropland area initially increased and then decreased, forestland area experienced a decline followed by growth, while built-up and unused land continuously expanded. Water bodies and grassland exhibited more complex change patterns. Land use transitions were dominated by conversions from cropland to forestland and built-up land. (2) The dominant factors influencing land use change in Neijiang City have shifted from elevation and slope to aspect, soil type, and NDVI, demonstrating the characteristic of a stable dominance of natural factors alongside an enhanced role of ecological-related factors. (3) Over the 30-year period, total carbon storage showed a steady increasing trend, with a cumulative increase of approximately 1.039 million tons. High carbon storage zones were mainly concentrated in forest-rich areas of the western region, whereas carbon storage declined in urban expansion zones. These findings provide a scientific basis for land use planning and ecological carbon sink management in Neijiang City and contribute to the coordinated advancement of regional ecological protection and carbon neutrality goals.