Association of Southeast Asian Nations (ASEAN) has consistently been China’s closest trading partner, and Guangxi Province has emerged as a vital trading hub connecting China and ASEAN, owing to its unique geographical location and supportive government policies. Although Guangxi’s service trade has grown significantly due to the Belt and Road Initiative, its global competitiveness remains relatively weak, and there is room for improvement in the overall volume of service trade. This study begins by reviewing existing research on the subject, revealing that ASEAN outperforms Guangxi in terms of total economic volume, total foreign trade, and total service trade. However, a closer examination reveals that Guangxi has an advantage in terms of industrial structure, service trade growth rate, and foreign trade composition. Using the market share index the revealed comparative advantage index, and the trade competitiveness index, the study identifies that Guangxi exhibits higher competitiveness in the service trade than ASEAN. Furthermore, using time series data from 2008 to 2019, an econometric model is developed using the Michael Porter Diamond Model to assess the determinants of Guangxi’s service trade competitiveness. The analysis concludes that gross domestic product positively impacts service trade, with service trade openness and foreign direct investment playing pivotal roles, outweighing their influence on ASEAN. In contrast, the proportion of the labor force has the least impact on Guangxi’s service trade competitiveness. In conclusion, this study provides recommendations and policy implications for enhancing the competitiveness of Guangxi’s service trade sector.