An addressing device for transmitting satellite TV signal is electrically connected with a satellite down-converter and at least one STB installed at a subscriber end. When the subscriber activates the STB for playing satellite TV channel programs, the satellite down-converter receives satellite signals provide by a satellite system end and processes the satellite signals to generate baseband satellite TV signal for input into the addressing device. Next, the addressing device receives GPS signal indicating the position where it is installed and then addresses the GPS signal, further executing digital security processes to converting the area address into an address signal having the same transmission frequency as that of the baseband satellite TV signal. Finally, the address signal is mixed with the baseband satellite TV signal for output to the STB.