In the “Internet Plus” background, resources opening-up, sharing, complementariness and integration among enterprises have become a hot topic in the business platform research. Internet business platform ecosystem is a product of the diversification of consumer demands, and also the inevitable requirement of enterprises to enhance their comprehensive competitiveness. Through literature research and expert scoring method, this paper extracts the five measurement dimensions of internet business platform ecosystem, namely scale, diversity, openness, equality and cooperation, and draws up the measurement scale for internet business platform ecosystem. At the same time, it also extends the general perspectives of business platform customer purchase research, simultaneously incorporates the construction of internet business platform ecosystem and virtual value chains of business platform into conceptual model of customer choice, puts forward relevant research hypotheses, and uses structural equation model to test the original conceptual model through a questionnaire survey. The results show that the Internet business platform ecosystem can bring customer lock-in effect; internet business platform ecosystem directly affects the perceived value of customer business platform; the impact of business platform ecosystem on customer purchasing behavior is greater than that of virtual value chain strategy. The results not only fill up the vacancy of internet business platform ecosystem research in theory, but also provide the guidance and basis for the development of platform enterprises.