Abstract: A conceptual model of dynamic mechanism is proposed by analyzing the internal and external forces that influence the development of cross-border e-commerce ecosystem. On the basis of qualitative analysis, the development trend of cross-border e-commerce ecosystem is simulated by Vensim PLE, and the impact of different factors analyzed by changing policy support factors, technological level factors and enterprises' own factors. The simulation results show that the government plays a stronger role in promoting cross-border e-commerce industry through strengthening customs supervision than strengthening commodity inspection and improving tax incentives. The development of information technology can promote the level of certification management and payment security. The improvement of cross-border e-commerce platform and cross-border logistics development can enhance the competitiveness of cross-border e-commerce and promote the development of cross-border e-commerce ecosystem.