This paper evaluates the sustainable development of cross-border e-commerce pilot zones and their impact on regional economic growth. A comprehensive performance evaluation system is constructed to assess the degree of sustainable development in the first five batches of cross-border e-commerce pilot zones in China between 2011 and 2020, which reveals significant regional differences and a clear “Matthew effect”. We also quantify the specific role of cross-border e-commerce pilot zones in promoting regional economic growth; specifically, we demonstrate that the level of sustainable development of cross-border e-commerce pilot zones has a significant positive impact on regional economic growth and show that these effects vary according to regional distribution, city level, and the degree of sustainable development of cross-border e-commerce pilot zones. On this basis, we explore the mechanism through which these factors influence one another and identify three main channels on which to focus for further development: industrial structure upgrades, institutional innovation, and consumption upgrades. Finally, based on empirical results, we propose differentiated policy suggestions for various regions and city levels through the provision of theoretical and practical support for promoting the healthy and sustainable development of cross-border e-commerce pilot zones and the stable growth of regional economies.