Against the backdrop of significant challenges in European and American markets, the Regional Comprehensive Economic Partnership (RCEP) presents a favorable opportunity for the Chengdu-Chongqing Economic Circle to chart a course for reform and openness. However, the existing literature focuses on China’s trade efficiency and potential with RCEP member countries at the state level, lacking a systematic study of the trade complementarity between the Chengdu-Chongqing Economic Circle and RCEP member countries. Particularly, there is a dearth of comprehensive and holistic analysis considering multi-agent network relationships. This paper, by employing the social network analysis method, calculates the goods trade competition and complementarity indexes between Chengdu-Chongqing Economic Circle and RCEP countries based on the six-digit commodity data provided by the United Nations Conference on Trade and Development (UNCTAD) and China Customs. Empirical findings reveal that between the Chengdu-Chongqing Economic Circle and RCEP countries, the trade complementarity considerably outweighs trade competition, indicating substantial trade potential. Specifically, Vietnam, Cambodia, and Thailand exhibit significant trade competition with the Chengdu-Chongqing Economic Circle. Australia, Singapore, South Korea, Malaysia, Thailand, and Japan exhibit significant trade complementarity with the Chengdu-Chongqing Economic Circle. Further analysis shows that the competitive landscape faced by the Chengdu-Chongqing Economic Circle is marked by cordial relations, while the trade complementarity environment is barely favorable. Notably, Chongqing and Sichuan have a high similarity in their commodity trade structures, with a trade competition index of 0.5954. Compared with previous literature, this study expands on two key dimensions. Firstly, it calculates the competitive and complementary indices of goods trade between the Chengdu-Chongqing Economic Circle and RCEP member countries, comprehensively revealing the trade dynamics between them. Secondly, by employing social network analysis, this study explores the trade network relationships between the Chengdu-Chongqing Economic Circle and RCEP member countries, shedding light on the former’s position, role, and critical connections within the network. This research partially explains the trade complementarity between the Chengdu-Chongqing Economic Circle and RCEP member countries. It provides differentiated policy support for optimizing the structure of goods trade between Chongqing and Sichuan, contributing to guiding the establishment of distinct open industrial systems, and fully leveraging the advantages of the Chengdu-Chongqing Economic Circle as a key node in the Belt and Road Initiative and the Yangtze River Economic Belt.