Based on the chaotic Logistic map and Chen map, this paper analyzes the encryption of audios and images in the IPTV system, proposes two chaotic encryption process of audio signal, and obtains the two chaotic keys of the initial value and the compression coefficient. Then it uses the two chaotic encryption methods in image signal, and compares the performance of two algorithms in terms of secret key amount, sensitivity, time complexity and so on. Ultimately, a new complex map is synthesized by Logistic map and Chen map, double keys are generated to encrypt the audio and image signals, so as to provide security for the transmission of IPTV programs in the internet.