The global and real-time characteristics of cross-border e-commerce can break the bondage of space and time, but it can't break through cultural differences. The layered decoding of cross-cultural communication analyzes three levels in intercultural communication from the three dimensions, which provides the theory of cross-cultural communication for cross-border brand promotion and customer service. With the development and integration of cultures, the paths of cross-cultural communication in cross-border e-commerce platforms also change dynamically. Both sides of cross-border e-commerce should have the courage to develop their own culture, adopt new practices and new methods to deal with cultural issues, and observe international commercial laws and international conventions.