In the context of profound restructuring of the global economic landscape and rising uncertainties, industrial chain resilience has become a critical factor in ensuring economic security and enhancing international competitiveness. As a major two-way investment country, China has consistently promoted the coordinated development of inward foreign direct investment (IFDI) and outward foreign direct investment (OFDI), which serves as an important pathway for strengthening the stability and competitiveness of industrial and supply chains. In this context, systematically identifying the mechanisms and constraints through which two-way FDI coordination affects industrial chain resilience holds significant theoretical value and practical relevance.Drawing on investment development path theory, institutional economics, and innovation system theory, this paper uses panel data from 30 Chinese provinces (excluding Hong Kong, Macao, Taiwan, and Tibet) from 2006 to 2024. It employs a coupling coordination model to measure the coordination level of two-way FDI and uses the entropy-weighted TOPSIS method to construct a comprehensive index of industrial chain resilience from three dimensions: foundation, resistance, and recovery. This study empirically examines the direct effect, transmission mechanisms, nonlinear characteristics, and spatial spillovers of two-way FDI coordination on industrial chain resilience. The empirical analysis yields five main findings. First, the coordinated development of two-way FDI significantly enhances regional industrial chain resilience. Quantile regression reveals that this promoting effect exhibits a marginally increasing trend as resilience levels rise. This conclusion remains robust after a series of tests, including variable substitution, exclusion of the financial crisis sample, winsorization, instrumental variable estimation, and the GMM method. Second, heterogeneity analysis shows that the resilience-enhancing effect is more pronounced in provinces with higher levels of economic development, stronger intellectual property protection and more abundant human capital. Third, mechanism tests indicate that business environment optimization and increased innovation support serve as two important channels through which two-way FDI enhances industrial chain resilience. Fourth, threshold effect tests reveal a double threshold for business environment, with the promoting effect continuously strengthening as the environment improves; innovation support also exhibits a double threshold, with the promoting effect showing an inverted U-shaped nonlinear pattern of first increasing and then decreasing. Fifth, spatial Durbin model tests demonstrate that two-way FDI coordination generates a significant siphon effect, producing negative spillovers on the industrial chain resilience of neighboring provinces.Compared with existing literature, the marginal contributions of this paper are threefold. First, from the perspective of the linkage between IFDI and OFDI, it systematically reveals the complete logic through which two-way FDI coordination empowers industrial chain resilience, addressing the gap in existing research regarding their intrinsic relationship. Second, by incorporating business environment and innovation support into a unified analytical framework and identifying both mediating mechanisms and threshold effects, it expands the research boundaries of factors influencing industrial chain resilience under open conditions. Third, by incorporating a spatial spillover perspective, it reveals the siphon effect of two-way FDI coordination, providing empirical evidence for regionally coordinated enhancement of industrial chain resilience. The findings offer valuable references for optimizing China’s two-way investment layout, improving institutional and innovation environments, and implementing differentiated regional policies, with important implications for advancing industrial chain modernization and high-quality economic development.