This article explores the mechanisms through which international diversification strategies and the global construction industrial context shape the competitiveness of emerging economic contractors. Drawing on an internal-external matching perspective, this study analyzes the matching between a contractor's international diversification ambidexterity (depth or breadth strategy) and industrial features (munificence or dynamism). Using panel data on Chinese contractors listed in Engineering News Record TOP 225/250 between 2012 and 2020, the empirical findings indicate that positive relationships exist between a contractor's diversification ambidexterity and competitiveness. Furthermore, we find two positive matching effects on contractor competitiveness: one is between depth strategy and industrial munificence, and the other is between breadth strategy and industrial dynamism. This study makes valuable contributions to both the theory and practice of international businesses for emerging economy contractors and the global construction market.