Abstract: A live TV broadcast method of digital interactive TV, which enables the whole network to share one set of CMTS for independent live broadcast: CMTS of each hub head-end is used for on-demand broadcast; Cable Modem aims to receive directives from users to seek downlink frequency corresponding to the IP address according to frequency IP list stored with IP addresses and downlink frequencies for advanced multicast. After that, data flow shall be sent to users through bridging by Cable Modem. As Cable Modem can directly perform the switchover, there is no need to use CMTS to receive uplink data. This is favorable for significant reduction of afflux of various interferences signals and off-line of Cable Mode, which can ensure normal and stable broadcast of programs in case of off-line.