Under the frequent occurrence of external environmental risks and in the context of breakthrough innovations driving new quality productivity, this study explores the intrinsic mechanisms by which supply chain integration affects enterprise breakthrough innovation. Grounded in supply chain integration and breakthrough innovation theories, we used statistical methods to analyze data from a sample of 209 valid enterprises. The study systematically interprets these mechanisms from the perspective of competition and examines the moderating effect of external environmental turbulence on competitive strategy. The results demonstrate that supply chain integration capability significantly and positively influences breakthrough innovation, with vertical and horizontal competing strategies acting as mediators. Additionally, environmental turbulence positively moderates the relationship between supply chain integration capability and horizontal competing strategies. The results of the study are of great theoretical and practical significance in promoting the integration of enterprises’ supply chains and enhancing their sustainable innovation capabilities.