The market structure and economic characteristics of Internet platform enterprises are the keys to solving the difficulties and challenges encountered in the anti-monopoly analysis of Internet platform enterprises, especially the definition and analysis of related markets. It is also an important prerequisite for anti-monopoly law enforcement agencies to correctly implement anti-monopoly policies in this field. Therefore, based on the theory of market structure and the perspective of anti-monopoly economics, this paper analyzes in detail the economic characteristics of Internet platform enterprises and their impact on market competition analysis from the perspectives of business model, network effect, market structure, and innovation performance, to find a breakthrough for the subsequent exploration of the relevant market definition methods of Internet platform enterprises.