Blockchain technology is one of the most popular technologies in recent years.It has been widely used in the field of e-commerce information security because of its characteristics of decentralization,trustworthiness and anonymity.Firstly,this paper introduces the blockchain technology from its basic principles,key technologies,application fields,and existing security risks.Secondly,the application of blockchain technology in the field of e-commerce information security is elaborated from several perspectives,such as data encryption technology,blockchain-based identity authentication,blockchain-based firewall technology,etc.Finally,the application challenges of blockchain technology in the field of e-commerce information security are analyzed,and the conclusions and prospects are summarized.