The construction of the Chengdu-Chongqing Economic Circle is a major national strategy to promote high-quality development in Western China. Based on panel data from 19 cities in Sichuan and Chongqing covering the years 2005 to 2022, this study employs a two-way fixed effects model to systematically examine the impact and underlying mechanisms of the language service industry development on high-quality economic growth in the region. The findings show that the development of the language service industry significantly promotes high-quality economic growth, particularly in the dimensions of openness, innovation, sharing, and coordination. Its effect is mainly realized through expanding foreign trade and attracting international talent. However, the industry’s driving force is significantly stronger in the core areas of Chengdu and Chongqing than in the peripheral cities, showing a pattern of “core polarization-peripheral collapse” and indicating regional development imbalance. Based on these findings, this study recommends: (1) establishing collaborative innovation hubs that integrate industry, academia, research, and application; (2) promoting tiered development of language service clusters to support spatial spillovers; (3) aligning industrial expansion with green development through the creation of multilingual environmental corpora and certification systems; and (4) strengthening interdisciplinary talent pipelines via adaptive training and lifelong learning programs. These measures aim to position the language service industry as a strategic engine for innovation, global engagement, and sustainable development within the Chengdu-Chongqing Economic Circle, while addressing coordination bottlenecks and enabling inclusive regional transformation.