Abstract: Breakthrough innovation is crucial for emerging countries to achieve technological catch-up and overtaking in the new round of scientific and technological revolution. However, no thorough conclusions have been drawn as to how to achieve breakthrough innovation in a short time with relatively weak technology accumulation and limited management experience. In this paper, based on patent data of V2X (including V2V, V2I, V2P and V2N) from CNIPA and USTPO patent database between 2001 and 2019, this study uses the social network analysis method, and combine a typical case of Baidu automatic driving R&D, to explores and analyze the mechanism of realizing breakthrough innovation from the perspective of the innovation subject and the innovation network characteristics in emerging countries. The findings suggest that: in terms of innovation subject, as the innovation resources of emerging countries are limited, compared with the developed countries which take industry backbone enterprises as the innovation subjects, the emerging countries take the enterprises collaborating with universities as the innovation subjects to concentrate innovation resources from enterprises and universities; in terms of innovation network relationship, as emerging countries need to turn overtaking competitors in a short period of time, the intermediary of breakthrough innovation network in emerging countries is more centralized on a few enterprise executives, who can use their alumni relationship of strong tie to promote the exploration and integration of innovation resources among enterprises and universities rapidly and effectively. Our research not only enriches the academic literature about the breakthrough Innovation and social network theory, but also gives out some countermeasures on how to break through resource constraints and achieve breakthrough innovation in a short period of time.