数字电视广播，高清晰电视和网络技术的发展使得数字电视视频通讯获得了广泛的应用。作为其重要的组成部分，条件接收系统是实现视频信息服务的必须条件。本文为CA条件接收系统的设计和应用提供了指导。-Digital TV broadcasting, high-definition television and the development of network technology makes digital TV access to a wide range of video communication applications. As part of its important component of conditional access system is the realization of video information services must be conditions. In this paper, CA Conditional Access System for the design and application guidance.