Abstract: Under the background of protectionism and anti-globalization, how domestic foreign direct investment enterprises should adjust their investment strategies and knowledge strategies to cope with changes in their own knowledge needs and changes in the international investment environment has become an urgent problem to be solved. In view of this, our paper firstly uses the knowledge structure theory and 10 Chinese cases to construct a theoretical model of enterprises' outward direct investment driving technological progress, and believes that the paths of outward direct investment driving enterprises' technological progress include: ① Knowledge base of foreign affiliates → reverse spillover knowledge (breadth × intensity) → knowledge absorption → knowledge base of domestic investment enterprises (number of knowledge reserves) → technological progress; ② knowledge base of foreign affiliates → reverse spillover knowledge (depth × intensity) → Knowledge absorption → domestic investment enterprise knowledge base (knowledge frontier level) → technological progress. However, in different investment stages, the utility of the breadth and depth of reverse spillover knowledge has changed, as shown in: In the early stage of foreign direct investment, investment enterprises are restricted by the disadvantages of ownership and internalization, and tend to choose a canyon-type structure characterized by depth or a pool-type structure with balanced and less investment activities; With the improvement of corporate ownership and internalization advantages, and the weakening of the location advantages of the host country, investment enterprises will gradually tend to choose a lake-type reverse spillover knowledge structure characterized by breadth. Compared with other research, our paper has three contributions: ① We combine knowledge structure theory with the concept of reverse spillover knowledge, exploring how reverse spillover knowledge promotes technological progress in investment enterprises from different dimensions of knowledge, aiming to fill the theoretical gap in the drive of technology progress by outward direct investment of enterprises. ② Our paper used internalization theory and investment development cycle theory to summarize the phased characteristics of foreign direct investment goals and knowledge structure adjustment of enterprises, aiming to extend the original static research perspective to a more practical dynamic perspective. ③ Our paper re-examines the differences between the dimensions of knowledge depth and knowledge intensity from a spillover perspective, addressing the issue of unclear concepts of knowledge intensity and knowledge depth in current research.