Abstract:This article is based on the new champions league after the outbreak scale expands unceasingly under the background of transnational merger and acquisition, using global mergers and acquisitions in taian database data, as well as countries financial data of listed companies, each enterprise''s cross-border m&a events as a natural experiment, using multiple phase double difference model to study the effect of operating risk of transnational merger and acquisition enterprise, the study found that: Cross-border mergers and acquisitions significantly reduce the business risks of enterprises. In order to solve the problem of bias, this paper also carries out PSM-DID test. The further influence mechanism shows that transnational M&A improves the management efficiency of enterprises through the "human capital effect" and solves the "bottleneck" problem of enterprises in core technology through the "technological progress effect", so as to reduce the business risk. From the perspective of heterogeneity, cross-border mergers and acquisitions have a stronger effect on reducing business risks in technology-intensive enterprises, large-scale enterprises, enterprises with a high degree of supervision, and enterprises in the east and central regions. At the same time, this paper also found that the large fluctuation of RMB exchange rate will increase the risk of multinational enterprises. Therefore, it is of practical significance to study the impact of cross-border mergers and acquisitions on the business risks of enterprises for long-term high-quality development and improvement of international competitiveness of enterprises.