<p>Understanding the factors influencing the reduction of industrial carbon intensity has become essential for sustainable development as concerns about the climate throughout the world grow. Although foreign direct investment (FDI) has been acknowledged in the literature as a possible contributor to emissions reduction, less focus has been placed on how economic complexity affects this relationship, especially in developing nations like China. To fill this vacuum, this study uses panel data from 2007 to 2020 to investigate how FDI inflows affect China’s industrial carbon intensity from the standpoint of economic complexity. We used a non-parametric moment quantile regression approach in recognition of the nonlinear complexity in the data, guaranteeing reliable and perceptive results. According to our analysis, FDI has the potential to lower the carbon intensity of Chinese industries, and its beneficial effects on lowering industrial carbon intensity in China are further enhanced by economic complexity. This discovery broadens our understanding of the complicated interactions among industrial carbon intensity, economic complexity, and foreign direct investment. The complex dynamics impacting industrial carbon intensity must be recognized by policymakers, who should also carefully examine how economic complexity plays a crucial role in determining these results.</p>