The invention discloses a multipoint safe videoconference 
system with an IP set-top box based on an H.323 protocol, which comprises a videoconference 
client module, a videoconference transmission module and a videoconference 
server module; the videoconference 
client module comprises the IP set-top box, a 
digital television and an audio / video acquisition and playing device and is used for realizing the identity 
verification of a videoconference user and the functions of acquiring, receiving and playing an audio / video content; the videoconference 
server module consists of a 
multipoint control unit (MCU) based on the H.323 protocol and is used for realizing functions of 
conference management, the integrity 
verification of the audio / video content, the identity 
verification of a user at a 
client, and the distribution and the 
processing of the audio / video content; and the videoconference transmission module realizes the transmission of the audio / video content between the user participating in a conference and a videoconference 
server by using a 
digital television network. According to the invention, a 
digital television user can realize a safe videoconference by the digital television with higher safety.