“Improve the scientific and technological innovation system” and “accelerate the implementation of the innovation-driven development strategy” is emphasized in the report of 20th CPC National Congress. Because of the separation of scientific and technological achievements and venture capital, universities are caught in the “dilemma” of low rate of scientific and technological achievements. Through theoretical deduction, a secondary incubation mechanism for venture capital to participate in university technological innovation were proposed. Further, using Grounded theory, this paper takes Tsinghua University as an example, to explore the “black-box” of university scientific and technological innovation. Through the three-level coding procedure, five categories and the logical relationship between them were extracted, and thus the secondary incubation mechanism model and theory were constructed. Based on this, this paper deepens the understanding of the system and mechanism of scientific and technological innovation, which will help promote the high-quality development of technological innovation and the integration of capital elements.