As a component of mobile communication, the pay-TV system has attracted a lot of attention. By using mobile devices, users interact with the head end system in service providers to acquire TV services. With the growth of mobile users, how to protect the privacy of users while improving efficiency of the network has become an issue worthy of attention. Anonymous authentication schemes for mobile pay-TV systems came into being. In this paper, we analyze the shortcomings of the existing authentication protocol and then propose an improved one, which is secure against stored set attack and user traceability attack. The proposed scheme is proved to be secure. Moreover, our new scheme performs better in efficiency and storage, compared with several other schemes.