Technological innovation of multinational corporations (MNC) is an important engine to drive the world’s scientific and technological progress, which plays an important role in the sustainable development of global innovation. With China’s high-tech industry from 2009 to 2020 as the research sample, this study empirically analyzes the impact of MNCs’ two-stage innovation on the innovation efficiency of China’s high-tech industry through the perspective of base regression, threshold effect, and regional heterogeneity. It was found that MNC research and development (R&D) efficiency and achievement transformation efficiency have a positive impact on the innovation efficiency of high-tech industries in China, with nonlinear features and regional heterogeneity. This study provides an empirical basis for the efficient use of MNC’s innovative resources and the sustainable development of China’s high-tech industry.