With the rapid development of Chinese economy, strategic alliances based on information sharing and cooperation attract an attention by more and more technology-based small micro enterprises, which is usually adopted in the competitive environment of small business. Based on literature review, questionnaire survey and empirical analysis, this paper attempts to probe the influence of alliance partner selection factors on alliance performance, especially the mediating role of partnership in the relationship between alliance partner selection factors and alliance performance. The results show that alliance partner selection factors are positively related to alliance performance, partnership has a significant positive effect on alliance performance, and partnership plays a partial mediating role in the relationship between alliance partner selection factors and alliance performance. It shows that small and micro enterprises in the choice of the way of alliance development, attach great importance to three characteristics, namely enterprise reputation, resources complementarity and enterprise compatibility. At the same time, small and micro enterprises should strengthen the communication information and improve the level of alliance trust to promote the harmonious and stable development of the alliance.It proves the effect mechanism of alliance parter selection on alliance performance through empirical study. It not only extends the theoretical basis of alliance formation of technology-based small and micro enterprises, but also has important practical significance to alliance partner selection.