In the new round of scientific and technological revolution and industrial transformation in the world, the integration and development of the Internet and various fields have broad prospects and unlimited potential. It has become an irresistible trend of the times and is having a strategic and overall impact on the economic and social development of all countries. Although, there are many theories that merger activities can bring positive effects to enterprises. However, the performance of Chinese listed companies after the merger is affected by many factors. Studying the motives, status and performance changes of Chinese listed companies M&A has positive significance for the development of enterprises.This dissertation first summarizes the development history and research status of the mergers and acquisitions of listed companies, and introduces the concept and classification of mergers and acquisitions. Then, based on the theoretical research of scholars in various countries, the theory of absorption and merger is further explained, and the status of China's Internet enterprise merger is summarized. In the empirical research section, 96 incidents of mergers and mergers of network companies listed on the Shanghai Stock Exchange and the Shenzhen Stock Exchange from 2010 to 2017 were selected as research samples, using event research method. The study of the merger effect on the short-term performance of the acquirer.Through empirical research, firstly, the short-term performance of the m&a company can be improved when the network company is the acquired party. This is because of the particularity of Internet companies. As an acquirer, traditional enterprises are themselves growing and sustainable when merging Internet companies, which will not affect their fundamental industries. Investors need the integration of Internet enterprises to bring more economic benefits, which will more actively promote the merger and acquisition of enterprises. Second, for large enterprises, m&a brings negative (-) growth of short-term performance. For medium and small-sized enterprises and start-up companies, the short-term performance brought by business combination is obviously growing.