Abstract: With the rise of cloud computing and the wide use of mobile platforms, this paper presents a mobile terminal authentication scheme in cloud computing environment, which is used to solve the problems of security in the traditional identity authentication technology. The programme with two-dimension code for information transmission carrier, combined with dynamic encryption keys, symmetric encryption algorithm and an inverse function. It realized the dynamic authentication of mobile terminal finally. According to the security analysis, the scheme with higher security and flexibility provides a simple structure and does not depend on third-party devices.