In the wave of the Internet economy, the use of effective marketing strategies is particularly important for new e-commerce companies. Taking Pinduoduo as an example, based on literature analysis and case analysis, this paper concludes that Pinduoduo uses fission marketing to rapidly expand user clusters and improve user viscosity through various fission marketing activities, successfully shaping a low-cost and affordable brand image. Although fission marketing has shortcomings such as excessive dissemination of information and security risks of leaking users' personal information, it is still an important reason for Pinduoduo's success. Based on the negative impact of fission marketing, this paper argues that e-commerce platforms should first control the excessive dissemination of information and improve the protection of user information, and secondly, each enterprise should formulate a fission marketing plan according to its own specific conditions. Finally, this paper puts forward ideas for the in-depth study of fission marketing theory.