The self presentation of online celebrities have contributed to obtaining fans’ support and accumulating social resources. This paper divides the self presentation of e-commerce online celebrities into two dimensions based on the self presentation theory: activity and content expressiveness. Then this research explores the mechanism of self presentation of e-commerce online celebrities on consumers’ purchase behavior. Analyzing the online celebrities panel data from January 2019 to August 2019, the results show that the activity of online celebrities positively affects the consumer’s purchase behavior; the activity of online celebrities promotes consumers’ purchase behavior by enhancing fans’ enthusiasm; the content expressiveness plays a moderating role in the influence of fans’ enthusiasm on consumers’ purchase behavior.