Control device for preventing unlicensed signal from getting to broadcasting television play device

Broadcast television signal includes two classes: digital and analog. The invention includes following steps: (1) when monitoring computer (MC) has monitored faults that dark field, silence frame, and lost video etc illegal signal disturb, and too large or small sound exist in video and audio signal of analog signal from satellite receiver (SR), fiber optic receiver (FOR), or bandwidth, PCR and PSI/SI indexes of digital broadcasting TV (DBTV) signal occur clear change; (2) MC sends command of switching off power supply automatically to power supply system of signal source devices of corresponding SR, FOR etc; (3) switching standby signal to DBTV multiplexer or analog broadcasting TV modulator etc in corresponding defective channel; (4) software of MC instructs sound card to send trouble alarm voice in corresponding channel; (5) after determining that illegal signal is removed, the watch turns on power supply system of SR or FOR by hand, and MC executes monitoring operation again.