Abstract:Entrepreneurs and their social capital have an important leading role in the growth and development of start-ups. Taking social capital as an entry point, this study summarizes the theories and literature related to offshore entrepreneurship, enterprise performance, social capital and technological research and development capabilities, and analyzes the interconnections between youth overseas social capital, technology research and development capabilities, and start-up enterprise performance. This paper constructs a model of the relationship between the start-up factors and start-up performance. Based on this, 260 companies established by young people from 2015 to 2018 were selected as the research objects, and relevant research assumptions were put forward and empirical studies were conducted to empirically explore the internal mechanism of young people"s social capital affected by technology R amp;D capabilities. To reveal the "process black box" of social capital affecting enterprise performance. The results show that the policy and market social capital of young people returning from overseas have a positive impact on the entrepreneurial performance, and the technological research and development ability has played a partial intermediary role in the relationship between social capital and entrepreneurial performance. Therefore, the paper presents the path and mechanism of youth return social capital affecting the performance of start-ups, and provides feasible development strategies for youth return integration of social capital, training core capabilities, and promoting the growth of start-ups.