Eliminating market barriers and promoting the rational flow of labor are of great significance for achieving regional synergy and fostering high-quality economic development. The level of labor market integration in the Chengdu-Chongqing Dual-City Economic Circle in 16 cities from 2002 to 2020 was measured using the relative price method, and the influencing factors were further analyzed. The study found that the level of labor market integration in the Chengdu-Chongqing Dual-City Economic Circle exhibited a wave-like pattern of consolidation but failed to achieve effective synergy. The labor market integration level was relatively high in the secondary industry and the service industry related to daily life. The level of economic development, government support, infrastructure construction, and rationalization of industrial structure were identified as the main factors influencing labor market integration in the Chengdu-Chongqing Dual-City Economic Circle, while the effects of industrial structure upgrading and opening up were relatively minor. The conclusions of the study provide actionable recommendations aimed at promoting the development of regional labor market integration and enhancing the capacity of the Chengdu-Chongqing region to establish a robust and distinctive dual-city economic cluster.